Abstract

The principle for autobalancing by the use of balls running freely in a ring concentric with the rotor center has been known for a long time. However, only in recent times has it been used in real machinery, such as grinding machines and laundry machines. By the increased need for higher precision, it is likely to come into use more frequently in the future. This means that it is important to know its application possibilities better. By using a time averaging technique, it has been possible to find analytical solutions to a number of problems. This article deals with; (1) the case of a rotor with anisotropic bearings and damping, where precise conditions for possible balancing are presented; (2) influence from inaccuracy of balancing ring and a rotor with longitudinal extension and thus having not only a point mass but also a moment of inertia; and (3) using two balancing planes to allow both static and dynamic balancing.