| The straight bevel gear is mainly used for transmission between the intersection shafts, itis widely used in automotive differential, mining machinery and other industrial fields.Because of the influence of manufacturing error, installation error and deformation in theprocess of gear meshing and other factors, the standard gear exists vibration, noise anduneven load in the transmission process. To solve these problems, many domestic and foreignscholars make the research on tooth-modification of gears, and they had made sometheoretical results about modification theory which greatly improved the effect of geartransmission.Because the topological structure of straight bevel gear is relatively complex, and themanual modeling is very tedious, so the efficiency of gear modification research is very low.So some scholars design the parameter modeling system of straight bevel gears, but most arein accordance with the back cone principle, or by curve fitting spherical involutes, so theaccuracy can’t be guaranteed. Besides, the design system of tooth-modification of spur bevelgear also has not been reported.Our research group studied the straight bevel gear on the tooth-modification theory, andput forward the isometric modification. The isometric modification effect is verified throughthe ANSYS dynamic finite element analysis, and the optimal modification parameters areacquired by orthogonal optimization test. Combined with the modification theory, themodification of spur bevel gear design system is developed in the integrated developmentenvironment of Visual Studio2008with SolidWorks2010as the supporting software, andwith C#as the programming language in this paper. The CAD system includes threefunctional modules which is the modeling module， the assembly module， and themodification module. In addition, there are some assistant function module which includethe main memory module and CAM/CAE interface module.The main function of modeling module is completing the parametric modeling of straightbevel gear. The users input the basic parameters of gears by the user interface of the basicparameters, and with some simple human-computer interaction, the bevel gear can bemodeled rapidly, which greatly improves the efficiency of modeling of bevel gears. And the spherical involute is generated by the "function of equation driven curve" which ensuresthe tooth profile accuracy.The main function of assembly module is to realize the automatic assembly of gears. Theusers only need to select the gear need to be assembled, then the system can automatically addmatching relation between the gears, and the assembly of gears can be completed quickly. Theassembly module also has the interface for the ANSYS, through which the ANSYS finiteelement software can be opened.The main function of modification module is to help users to complete the rapidmodification of bevel gear. And it is consists of isometric modification and tooth profile linepractice. The users select gears need to be modified, and then chose the modification methods.The users get the amount of modification by finite element analysis of ANSYS, and then inputother modification parameters which can also be generated automatically by the system.Finally, the bevel gear modification can be realized with the human-computer interaction.The storage function can realize storage of the model data, such as the basic parameters,bevel gear indirect parameters and shape parameters etc. The CAM/CAE interface can helpthe system connect with the Cimatron software and the finite element analysis software ofANSYS. And it facilitates the subsequent analysis of CAM and CAE.The tooth-modification system of straight bevel gear greatly improves the efficiency ofmodification research, and reduces duplication of labor. It lays the system foundation for theuniversal of straight bevel gear modification theory. At the same time, the design system canalso provide accurate models of gear and gears pair for the motion simulation, finite elementanalysis, bevel gear mold design and CAM. |
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