Research On Theory And Method Of Tooth Surface Skiving Machining For Equal Base Circle Bevel Gear

Owing to its well bearing capacity,the spiral bevel gear with hard tooth surface in the mainframe equipment is applied more and more extensively,however,due to the large volume,the high price and the low machining efficiency of its cutting machine,which requires complex manufacture technology,and most of the core processing technology was mastered by foreign manufacturers,although the related domestic research follow one another,most of them concentrated in the soft tooth surface.As a new kind of curve bevel gear,equal base circle bevel gear(EBCBG)can totally replace the traditional types,because of its processing equipment is simple,and the processing cost is low.EBCBG is machined by way of form milling,in two axes linkage cutting machine,its cost is lower,its machine structure is simple and miniaturized.the fingershaped carbide cutter used is difficult to produce,and also the finger-shaped grinding wheel wears quickly and its intensity is low,the finish machining of EBCBG with hard tooth surface is difficult to achieve,which result in the low machining efficiency and poor machining surface quality,which greatly restricts the wide application of equal base circle bevel gears..In this paper,EBCBG with hard tooth surface is chosen as the research object,On the basis of existing basic principle of EBCBG,combined with the research achievement in the field of gearing analysis theory and numerical control technique,the tooth surface scraping theory and method was studied systematically,details are as follows:The tooth surface scraping theory of EBCBG.Based on gear meshing theory and principle of differential geometry,the feasibility of skiving machining was discussed.According to the forming theory of EBCBG,the processing coordinate systems were established,and the equations of tooth surface enveloped by skiving machining were derived.Using the MATLAB software to write programs,three-dimensional surface of EBCBG is built in round billet coordinate system.On the basis of tooth equation,the difference surface between scraping tooth surface and theoretical tooth surface is contrasted,and the normal machining precision of scraping the tooth surface is analyzed.The research above provides a theoretical basis for the analysis of the subsequent contact analysis and scraping simulation processing.Tooth contact analysis(TCA)of EBCBG in skiving machining.The files whichcontains point data of tooth surfaces are extracted from scraping tooth surface equation to import UG software,the models of gear wheel and pinion are established.According to the theory of finite element analysis,import the models above into ABAQUS,divide mesh grid after assembling,and analysis of statics is carried out.According to stress and strain at different times,the contact path of diagram concave and convex surface between gear wheel and pinion is obtained.According to the tooth equations of EBGCG,based on gear meshing theory,nonlinear equations is established by MATLAB,the tooth surface meshing points and transmission error of gear tooth surfaces are found out,and their graphs and meshing contact trace below are drawn,by the result of TCA,the meshing and transmission of scraping tooth surface performances well.By the two kinds of contact analysis results,the feasibility and correctness of skiving machining for the surface of EBGCG are fully verified.The simulation research for the numerical control(NC)of skiving machining EBGCG.According to the NC machining principle of EBGCG,the motion characteristic of forming EBGCG are analyzed,the position and posture of cutting tools in the process of skiving machining is programmed.Through the post processing,the explicit function expression for motion coordinates in the NC skiving machining was obtained.And the simulation of NC skiving machining is conducted in VERICUT software.The simulation results show that,the process of NC skiving machining is correct and feasible.