Investigation of Adaptive Spindle System with Active Electromagnetic Bearing

Available motor spindles and tool chucks generate uncontrolled process deviations at several eigenfrequencies leading to geometrical and surface distortions. A demand for highest precision motor spindles, tool chucks and cutting tools arises for advanced cutting processes, free from tool deflection and vibrations. This paper targets a new design of a non-typical Adaptive Spindle System (AS) with an additional electromagnetic bearing based on mechatronics and adaptive control methods for advanced cutting technologies and proposals drafting on AIS development. The static and dynamic performance determination of the AS at speeds of up to 15,000 rpm has been performed on a test bench with actuator stimulated forces and displacement sensors. The analysis of time-domain and amplitude-frequency characteristics confirmed the demand in adaptive closed-loop control methods for compensating tool deflections and vibrations at eigenfrequencies.