Three-Dimensional Automatic Modeling Of Spiral Bevel Gears With Equal High Teeth And Precision Forging Die

Spiral bevel gears are widely used in gear drives with high circumferential speed,large bearing capacity,stable transmission and low noise due to their advantages such as large overlap coefficient,strong bearing capacity,smooth transmission and low noise,etc.They are indispensable key transmission parts for vehicles,vessels,tanks,airplane,oil rigs and other equipment.Equal high teeth are one of the most important gears in spiral bevel gears.Compared with the not-equal high teeth,equal high teeth have higher bending strength and longer contact fatigue life,which are more prominent advantages.However,more and more researches are made on equal high teeth gears.However,its modeling and manufacturing process are more complex,and the traditional manual modeling cannot meet the flexible production requirements due to its low modeling efficiency and high modeling cost.Therefore,it is of great significance to study the automatic modeling method of spiral bevel gears with equal high teeth and realize its three-dimensional modeling automation to promote the modeling and manufacturing efficiency of equal high teeth gears,as well as to promote its development and application.In this article,take spiral bevel gears with equal high teeth as the research object,established the parametric equations of equal high teeth gears,and take UG/Open GRIP as the secondary development tool,realized the three dimensional entity model,hot forging and the forging die automatic modeling of equal high teeth gears,on this basis,equal high teeth gears forging manufacturability also has carried on the preliminary discussion,the main research work is as follows:Based on the formation principle of spherical involute,the space rectangular coordinate equation of spherical involute is deduced.Based on the formation and properties of the extended epicycloid,the space rectangular coordinate equation of the extended epicycloid was derived,and the calculation formula of the helix angle at any point was established.Based on the detailed analysis of the meshing principle of spiral bevel gear with equal teeth,the calculation formulas of base circle,dividing circle,tooth tip circle,tooth root circle radius and cone height were established,and the N-type teeth and G-type teeth under different conditions were studied.With the help of UG/Open GRIP secondary development tool,the automatic modeling method of gear substrate,tooth shape solid and tooth root fillet was established,and the rapid automatic modeling of its three-dimensional solid model was realized.Considering the forging technology of spiral bevel gear with equal teeth,the automatic modeling of forging allowance,forging fillet and flicking,gear dressing and so on was carried out,and the 3D automatic modeling system of spiral bevel gear with equal teeth and its hot forgings was developed.According to related standards of gear forging die design and features of gear forgings,the two-dimensional model of the precision forging die of spiral bevel gears of with equal high teeth is designed in accordance with the actual situation,through GRIP secondary development tools,developed the precision forging die of 3d entity model modeling module,realized the spiral bevel gear with equal teeth precision forging die automatic modeling.The hot deformation behavior of 20CrMnTiH steel at high temperature was studied by hot compression test,and its constitutive model and hot working diagram were constructed.The finite element model of precision forging process of spiral bevel gear was established,and the finite element simulation of its forming process was realized.A kind of blank section shape was designed,and six groups of shaped section blank were used to simulate the forging of spiral bevel gear with equal height teeth.The reasonable blank was optimized,and the comprehensive goal of no outer flash and lower forming load was realized.