Spline description of non-typical gears for belt transmissions

The usage of noncircular gears makes possible to get better characteristics of the transmission. This problem is widely studied in the case of regular noncircularity, e.g., when a gear is of an elliptical or cycloidal shape. In this study, there are taken into account non-typical irregular gears. The design of such gears involves more advanced techniques, in particular there has to be applied a numerical treatment to get a mathematical description of the gear profile. In the paper, we discuss a parametric spline interpolation of the third degree and we give an example of such approximation. We also present a prototype drive making that the belt transmission has changeable kinematical features.