New electromagnetic ring balancer for active imbalance compensation of rotating machinery

New electromagnetic ring balancer for active mass imbalance compensation of rotating machinery is proposed in this paper. This type of active balancer maintains the balanced condition of machine by permanent magnets rather than clutch and external energy. Firstly, the imbalance compensation principle is presented, and then the balancer design is completed. For the proposed balancer, the actuation principle and operational process are presented in detail. Based on the finite element stable-state and transient calculations, the reasonable design parameters are obtained to direct the development of balancer prototype machine. The relative experimental tests are completed to validate the balancer design and fabrication. The proposed balancer has a simple structure, a wide range of balance capability, a stable and smooth operational process and a desirable vibration response. This study shows that the machine tool spindle integrated with active balancer indeed has an expected mass imbalance compensation function, and the mass–radius product of 6.03–38.55 g cm can eliminate the vibration of 0.0021–0.1076 gravitational acceleration.