Fabrication and test of an electric spindle integrated with an electromagnetic balancer

This paper focuses on the development of an electric spindle integrated with an electromagnetic ring balancer. Firstly the electromagnetic ring balancer is designed and then 3D model of self-balancing spindle integrated with this balance er is created. Based on the design, an on-line balancing principle of self-balancing spindle is proposed. The prototype machine fabrication process of the balancer´s key parts including coil, counterweight disc and toothed disc are discussed. For an actual spindle, the detailed design and development of this balancer are done, particularly the balancing craft of the combined rotor is done on a balance machine before delivery. By installing the balancer on the front end of spindle using flange, a self-balancing spindle prototype is obtained. In workshop, the vibration test of the developed self-balancing spindle is carried out in the range of 3000r/min to 9000r/min. The result shows the developed self-balancing spindle has a vibration velocity below 0.5mm/s. Finally the two eddy current sensors are applied to evaluate the vibration suppression capability of balancer, the experimental result is that about 15um peak-peak value can be eliminated when the correction value of balancer changes from 0 to 38.55g.cm in 3000r/min.