Input Torque Balancing Using an Inverted Cam Mechanism

Input torque balancing is a well known way to reduce the fluctuation of the camshaft speed in high-speed cam-follower systems. This paper describes a methodology to design an inverted cam mechanism (ICM) that provides quasi perfect input torque balancing at any speed, provided that the cam-follower system is purely inertial. The ICM was introduced in the fifties, but the design methodologies proposed by Meyer zur Capellen (1964) and Michelin (1979) are respectively erroneous or too rough an approximation and are here corrected. The design methodology is based on a novel way to nondimensionalize the dynamic equation that governs the inverted cam design, in order to keep the theoretical results as generally valid as possible. It is applied to a design example, showing that there are two basic design parameters to be chosen. Based on a design chart, these parameters are determined in such a way that the ICM size is minimized, taking into account technological and dynamical mechanism constraints.