New electromechanical balancing device for active imbalance compensation

New type of electromechanical balancing device that can be used for active compensation of variable imbalance of a rotational machine is proposed. The balancing device is in a shape of ring with a number of grooves displaced around the axis of rotation. Balancing members (steel balls) are placed into the grooves, and a driving electromagnetic device is used to actively control the movement of the balancing members. The balancing members are moved between radially inner position and radially outer position of the ring. When the proposed device is attached to a rotating machine, the driving electromagnetic device is activated to generate a force on a selected balancing member, so as to displace it and to vary the balancing status. The main advantage of the proposed device is in its capability to reduce rotational imbalance in applications where the value and position of imbalance is variable. The paper presents both finite element analysis results and experimental results of prototype design.