Research On Optimal Matching Of Skiving Process Parameters And Tooth Surface Accuracy Charateristics

Gear is the key basic part of many equipment,and its machining quality directly affects the transmission performance of mechanical equipment.Gear Skiving is an emerging gear processing technology in recent years.Compared with the traditional hobbing,gear shaper and other processes,it has the significant advantages of high efficiency,high precision and environmental protection.It is gradually becoming the preferred process for processing complex and precise inner gear rings on industrial robot reducer,automotive gearbox and aeroengine reducer.However,the meshing noise of the reducer is often too large because of the poor cutting texture of the tooth surface.It is urgent to find out the optimal matching relationship between the cutting parameters and the tooth surface topography.In this thesis,Aiming at improving the quality of tooth surface in gear machining,the optimal matching relationship between the parameters of gear machining and the precision of tooth surface was studied by establishing the mathematical model of the enveloping motion of gear machining with eccentricity error.Specific research contents are as follows:(1)A mathematical model of tooth forming envelope motion with eccentricity error was established.Based on the meshing principle of intersecting axes,the moving coordinate system of gear machining was established,the conversion relationship between each coordinate system was defined,and the forming model of gear machining tooth surface was established.By deducing the relative velocity between the tool and the workpiece,the normal vector of the tooth surface and the meshing equation,the sweep trajectory of the tool space was obtained,and the expression model of the residual height difference of the tooth direction including the error of the tool eccentricity was established.(2)The mapping law between the gear skiving process parameters and the tooth surface accuracy is studied.Based on the spread envelope motion model with tool eccentricity error,the influence of eccentricity error on the accuracy of the tooth surface is analyzed,the mapping relationship between the axial feed rate and the accuracy of the tooth surface is obtained,and the influence of the ratio of the number of tool teeth to the number of workpiece teeth on the accuracy of the tooth surface is revealed.(3)A method of tooth surface error optimization based on tool number optimization is proposed.An optimization model was established to minimize the residual height difference of the tooth surface under the constraint conditions of the eccentricity error of the tool,the number of tool teeth and the axial feed rate.A GABP neural network optimization model was established,and a tooth orientation error optimization matching method was proposed based on the optimized tool number.The experimental results show that the machining accuracy of the gear surface is obviously improved by using the optimized process parameters compared with the surface quality of the gear surface without the optimized process parameters,which verifies the correctness of the mathematical model of enveloping motion with eccentricity error and the proposed optimization method.The research content of this paper can provide theoretical guidance for the parameter design of gear tool and the optimization of gear process parameters.