Research On Visual Simulation Algorithm Of Spiral Bevel Gear's Tooth Surface Forming Process

As a part with complex sufaces, the design and machining process of spiral bevel gear is very complicated, so it is necessary to verify the rationality of machine tool adjustment parameters through adjustment and test-machining before formal machining. However, that process prolongs the production cycle of spiral bevel gear, increases the production cost and wastes resources. These problems can be well resolved by using virtual machining instead of traditional adjustment and test-machining. Virtual machining not only could verify rationality of machine tool adjustment parameters, but also could provide accurate geometry model to TCA analysis and finite element analysis. In this paper, visual simulation algorithm of the forming process of spiral bevel gear's tooth surface is studied and realized in virtual environment.In order to solve the problems existing in geometric simulation of cutting process, such as slow speed, low precision and lack of independence, slice algorithm is presented. That is slice the gear blank and establish the mathematic model of slice characteristics firstly,then get the intersection of tool model and slice characteristics, finally obtain the model of spiral bevel gear through selecting the characteristic elements between the characteristic set of adjoining time. Because the algorithm is based on the existing programming language Visual C++ 6.0 and OpenGL graphics library, it can be isolated from the commercial software. Through using mixed programming of Matlab and VC, the accurate result of intersection calculation can be accomplished rapidly.According to the production requirements, the simplified models of tools and gear blanks are proposed, whose dimensions can be controlled by the parameters inputted by users. The display model of tool and 3-dimensional reconstruction model of spiral bevel gear are established according to their changing characteristics during machining. The model of gear is expressed to several NURBS surfaces. Through drawing and cutting these NURBS surfaces and reconstructing the tooth surfaces by using triangular faces, the realtime display and reconstruction of spiral bevel gear can be realized rapidly.Besides, in order to realize the simulation of machining process of traditional gear milling machine and numerical control generator, their structure and motion principals are studied.