Generation of Identical Noncircular Pitch Curves

Abstract

In this paper the theory and algorithm for generating pairs of identical noncircular conjugate pitch curves are presented. A set of criteria for two identical rigid bodies engaging in conjugate rolling motion is established. Based on these criteria, an algorithm is developed, which can be used to design this type of rolling pairs with almost unlimited profile varieties and any number of lobes. Geometrical conditions for having C1 (or slope) continuity at the intersections of tips and roots of lobe profiles are also established. A family of similar profiles can be designed at the same time by using a single parameter, the pitch noncircularity, via a dimensionless analysis. Results from this investigation should have applications to the design of noncircular gears and lobe pumps.