Improving the geometry design of cylindrical cams using nonparametric rational B-splines

A procedure for the synthesis and analysis of the surface geometry of cylindrical cams with oscillating roller followers is presented. The interpolation of nonparametric rational B-splines is used to synthesize and refine the dwell-rise-dwell motion function of the follower. Given the synthesized follower motion, an approach based on the theory of envelopes of a 1-parameter family of surfaces is used to determine the surface geometry of the cylindrical cam profile. To show the effect of the refined follower motion on the cam surfaces, the geometric characteristics for the pressure angles and principal curvatures of the cylindrical cam surfaces are analysed. Favourable results obtained by using the rational B-splines are illustrated in an application example, and they are compared with those obtained by other traditional methods.