The Research And Development Of Noncircular Gear CAD/CAM System Based On ObjectARX2004

Because of developing of computer and numerical control technique, the manufacture technique of noncircular gear is improved, but the design of that is still a complicated thing. For example, we must use integral method in computing the arc length of noncircular gear, but the expression is very complex and the computation workload is big, it increases the difficulty and time of design. So, it is very important for designer that a noncircular gear CAD/CAM system with friendly interface, strong calculate ability, high efficiency, function of generate NC code. And that is just the reason and meaning of the research.Using ObjectARX2004 SDK in VC++7.0 IDE, a noncircular gear CAD/CAM system (NCGS) is developed. Because of the ARX and MFC technique is adopted in dialog box design, COM technique in toolbar and menu design, the application program interface(menu, dialog, toolbar) is integrated the AutoCAD environment and easy to operate.Firstly, the joggle principle of noncircular gear is researched and engineering mathematics model is built in the paper, the pitch curve equation, tooth profile equation, part pitch, arc length of pitch, close state judgement of pitch curve, convex state judgement of pitch curve, pressure angle judgement etc. problems are solved. Secondly, we adopt the Object-Oriented (OO) software method instead of traditional mechanical CAD software method(Process-Oriented), and analyze the system using UML(Unified Modeling Language). Starting from requirement, the system package diagrams, entity class diagrams, interface class diagrams, and connection diagrams of theirs are given, so the static state model is build. Then the activity diagrams, sequence diagrams are given, the dynamic state model is build. And that establish the good base for latter program work. Finally, directed by OO idea, a NCGS system with the function of pitch curve design, ellipse gear design, eccentric gear design, joggle simulation, CAM is accomplished. The design idea, key arithmetic, class description, partly code are detailedly introduced in the paper.After testing, it shows that the NCGS works well in AutoCAD2004, and can satisfy the design of noncircular gear. So, the expected target is achieved.