Abstract: Design and calculation of non-circular gears based on non-circular pitch curves are more complex than circular gear’s. Because of variety of tooth shape, non-circular gears can not be used to model by arraying, mirroring and other methods. The current three-dimensional mechanical CAD software cannot directly model non-circular gears. Using Visual Basic language to carry on secondary development of SolidEdge, it can realize the function of root cutting check, convexity check and pressure angle calculation, can establishe a three-dimensional modeling system of non-circular gears, can provide a method of three-dimensional modeling parametric design for the non-circular gears. The generated gears can be used for assembly design, motion simulation and computer-assisted teaching, etc.

Key words: computer application, three-dimensional modeling, parametric design, non- circular gears