ON THE MANUFACTURING TOLERANCE OF DISK CAM PROFILE

Abstract

For a given rocker-roller cam system, the mathematical expression of the cam profile was first derived from the desired displacement function utilizing theory of gearing and differential geometry. Furthermore, the variance in the cam profile due to cutting tolerance was modelled using the Monte-Carlo method as set of normally-distributed random numbers. Based on these models, the deviation from the desired motion resulting from manufacturing imprecision can be calculated by reversing the procedure. An optimization scheme was then employed to identify the optimal configuration which minimizes the motion deviation. It is found that the kinematic error of the mechanism can be minimized if the pressure angle of the mechanism remains small. Also the usefulness of the methodology developed for designing a rocker-roller cam mechanism taking the fabricating error of the cam profiles into consideration is demonstrated.