Research On Gear Flank Twist Prediction And Gear Error Compensation For Generating Gear Grinding

Automotive gearbox is developing towards low noise and high power density,and the requirements for gear machining accuracy are becoming increasingly high.In this paper,by using the gear meshing principle,the equation of gear meshing track and gear flank twist considering tooth profile error and machine tool installation error are derived to improve the accuracy of gear.Through orthogonal experiments,the influence of modulus,number of teeth,profile corrected value and helical angle of gear on gear flank twist is analyzed.At the same time,by deriving the mapping relationship between the motion compensation of the machine tool and the gear tooth profile error,this paper calculates the motion compensation of the generate gear grinding machine,which reduces the gear tooth profile error.The work is of great significance for accurately predicting and controlling the accuracy of gears.The main contents include:Based on the profile modification curve,axial modification curve,and gear modification formula,an analytical formula for modified gears considering profile modification and axial modification is established.A three-dimensional model of the modified gear considering profile modification and axial modification is obtained based on the analytical formula.Based on the basic relationship of gear meshing,the equation of tooth profile modification curve,the equation of gear meshing trace is obtained by using analytical geometry.Based on the equation of gear meshing trace,the calculation formula of gear flank twist considering tooth profile modification is obtained by using analytical geometry.The influence of relative positional errors of gears and grinding wheels on gear flank twist is analyzed using the kinematic relationship of machine tools.The influence of gear tooth number,module,spiral angle,and profile corrected value on gear flank twist is analyzed using orthogonal method.The results show that the module of a gear has the greatest impact on gear flank twist,while the profile corrected value has a small impact on gear flank twist.Reducing the gear tooth number and spiral angle appropriately,and increasing the profile corrected value can reduce gear flank twist.The basic coordinate system of the generating grinding machine tool is established,and the mapping relationship between the motion compensation amount of the machine tool and the gear tooth profile error is obtained by solving the motion relationship of the generating grinding machine tool,the transformation relationship of the coordinate system of the generating grinding machine tool,and the gear meshing principle.The motion compensation amount of the machine tool is obtained by solving the mapping relationship using the Newton method.By importing the motion compensation amount of the machine tool into the CNC machine tool to process the gear,and detecting the gear tooth profile error before and after the gear machining error compensation,the results show that:after the gear machining error compensation,the gear tooth profile error is reduced,and the gear meets the production requirements,verifying the effectiveness of the gear error compensation method.