Research On CAD/CAM Technology Of Noncircular Gears

The gear transmission is the most popular form in the machinery transmission, and the circle gears transmission with a fixed-transmission ratio has been used widely among them. In some special mechanisms, which need to achieve variable transmission ratios, the circle gears hardly meets the requirements, because of it's special transmission performance, but noncircular gears can realize the special movement with its special characteristic in kinematics and geometry. Noncircular gears were not used widely in industry. Because it's designing and machining technology is very difficult for the noncircular pitch curve, even though the meshing theory of noncircular gears has been relatiely mature. This thesis mainly study on CAD/CAM technology of noncircular gears. In order to realized the precision manufacturing and wirdely using.Firstly, according to the meshing theory of gear, aimed at the different transmission ratio and design parameters, the mathematical model of noncircular gears pitch is established. Using MATLAB software, some common noncircular pitch curve and transmission gears ratio curves were calculated and analyzed. The closed property of noncircular gears, undercutting condition, pressure angle, pitch curve convex-concave characteristic value, were examined. Using the elliptic gears as an example, while analyse the High-Order elliptic gears transmission radius vector, the relationship between the eccentricity and the variation of transmission radius was developed. Adopt the "convert gear form" method, the noncircular gears tooth design process is developt. Base on the MATLAB software on the noncircular gears tooth parameters calculation. Using CAXA software as design tool, the drawning files was imported, and then input the Solidworks software, the three-dimensional simulation of noncircular gears was obtained. Finally, the noncircular gears machining process simulation and design were obtained in the CAXA softare. According the 3B processing code, the noncircular gears were machinged with wire cut EDM (WEDM) machine, the validity of experiment process content was examined.Moreover, in order to prove the universality of noncircular gears design and manufacturing method. Through the parametric modeling, processing simulation, process design and processing tests, the CAD/CAM techology of other types of common noncircular gears (Pascal Curves and eccentric gears) were analysed.