Study On Modeling And Forging Process Of Spiral Bevel Gear Based On UG Open/GRIP

High-performance spiral bevel gears are key components in automotive drive axles.Obviously,the quality of bevel gears directly determines driving effects and carrying capacity,which is the core safety factor of automobiles.However,the tooth surface structure of the spiral bevel gear is complex and the tooth shape modeling is very difficult.Considering that the traditional modeling method can’t meet the flexible and variable production requirements,studying the geometry of the tooth surface and the design method of the gear and realizing the automatic modeling of the spiral bevel gear are of great significance for improving modeling efficiency and ensuring modeling quality.In this paper,automobile spiral helical bevel gear was taken as the research object and UG NX was used as the development platform.The research was mainly on the derivation of tooth surface curve equation,the modeling and development of tooth profile and the design and optimization of gear forging blank.Besides,the spiral bevel gear automation modeling module was developed with UG/Open GRIP.The main research work is as follows:Theoretical basis of the gear three-dimensional design was studied by deriving spatial curve parameter equation involved in gear modeling process.The curves included:plane involute,spiral,spherical involute and toothed arc.In order to construct main geometry of the bevel gear,tooth surface equation based on the cone angle was derived.In addition,the cones in the contour gear were established by the simultaneous equation of cone projection line and spherical involute.Offset distance and the size and position of basic arc were deduced on the base of spherical involute.The means of using GRIP in solid modeling was expounded and GRIP language module and common modeling statements were comprehensively analyzed.To develop automatic gear modeling program,the basic structure of GRIP statement and the function of various statements in solid modeling were clarified.What was more,the syntax and string errors were analyzed and GRIP DEBUG method was summarized.So as to create tooth profile and space surface,modeling programs of spur gear,helical gear,straight bevel gear and spiral bevel gear were developed based on the parameter equations.This program was integrated in the form of gear library menu bar and interactive toolbar with UG/Open MenuScript,which improved the call speed of the automatic gear modeling program.Considering the modeling method of finite element analysis in forging process,the forging blank model library of gear was developed with GRIP language and the scheme of hot forging numerical simulation was carried out.The FEA results showed the influence of wall thickness on the hot forging of contour tooth helical bevel gear.