Research And Development Of CAD/CAM System For Non-circular Gears Based On VB

Although non-circular gears have special transmission character in kinematics and geometry, but it were not used widely in industry. It is mainly because designing and machining non-circular gear is very difficult. If computer science and numerical technology be applied in designing and machining non-circular gears, making non-circular gears will be easy. In order to computer science and numerical technology be applied effectively in designing and machining non-circular gears, the best way is developing special CAD/CAM system for non-circular gears. First, this paper summarizes the development history of non-circular gears, and introduces the newest development of computer science and numerical technology applied in non-circular gears. Then introduces the basic theory and its development so as to serves as modeling when carrying out system; uses Visual Basic program to develop the CAD/CAM system for non-circular gears; designs modules of pitch curves of non-circular gears, including giving transmission ration function between a non-circular gear and the other, and giving pitch curves of the driving non-circular gear, and a function fitted for driving non-circular gear and driven non-circular gear, and so on, develops the module of geometry of non-circular gears. At last, designs the module of machining. System Solutions is better. It obeys the basic principles and notices. When the programmers is programming, they face the objects. Increasing and decreasing and modifying are very easy. The system interface and exchanging information between system and users are very convenience. It develops a controller in visual basic program for automatically calculating the value of a function. When you input an expression of a ration function, using the controller, the system automatically finish the designing of pitch curves. In this paper, the author gives example for each other. The author simulates the processes of machining non-circular gears using VBA program, and gets the geometry of ellipse gear. The curves of the geometry of ellipse gear are vector and it is convenience to program the numerical control program. In the machining module, the author designs how to create numerical control program automatically using shape cutter or mesh cutter machinery. The author tests every module, and results proved the modules are correct.