Lateral motion of a flat belt in an open-end belt system with in-plane misalignment

Abstract

Belt systems with flat belts and rollers have been widely used in power transmission and article transport mechanisms. In belt systems, the relative tilt of adjacent rollers, called misalignment, causes the flat belt to move in the width direction (lateral belt motion, also referred to as tracking). However, the mechanism of the lateral belt motion has not been precisely clarified. Understanding the mechanism of the lateral belt motion not only helps achieve the stable operation of the belt system but also is useful for web transportation, such as films and thin sheets. The lateral belt motion in the open-end belt system with in-plane misalignment was investigated using an experimental setup. The experiment shows that, in the open-end belt system, the lateral belt motion stays in equilibrium where the stream of the belt becomes perpendicular to the axis of the downstream roller. We, herein, proposed a formulation that predicts a lateral belt motion in the belt system using a relative displacement of the belt between rollers, distance between adjacent rollers and parameters of the crown roller. We observed that, in an open-end belt system, the lateral belt motion is influenced by the relative displacement of the belt between the rollers rather than the misalignment angle between rollers.