Reduction of spindle vibrations in milling machine by active magnetic bearing

In this study, a three-dimensional dynamic model of a milling machine is proposed. The cutting forces of the face milling process were obtained according to the cutting parameters by means of computer simulations and experiment. The cutting forces excited the dynamic model of the system. Relative displacements of the contact point of the cutting tool and the workpiece were obtained by using forced vibration analysis. These displacements affected machining accuracy of the milling machine. Therefore, radial and axial electromagnetic bearings were designed for the active control of the system and they were adapted on the spindle of the milling machine. Thereby the electromagnetic force produced around the rotating spindle reduced vibration amplitude of the cutting tool. The system was operated with and without active control and both these cases were compared. It was revealed that active control diminished cutting tool vibrations and improved machining performance