Vibration control of a high-speed air-bearing spindle using an active aerodynamic bearing

A novel high speed air-bearing spindle is proposed as a tool spindle for small diameter of cutting and grinding tools. The spindle vibration at high rotational speed is suppressed by an active aerodynamic bearing incorporated into the spindle. For generating aerodynamic damping force, the wedge angle on the aerodynamic bearing surface is controlled by piezoelectric actuators. By using several control tactics, the effect of the active control of the aerodynamic bearing on the spindle vibration is analyzed. Experimental result shows that the amplitude of the spindle vibration can be suppressed to be 0.1μm at the rotational speed of 50,000 min-¹ (833 Hz). Final goal of the study is to suppress the amplitude of spindle vibration less than 0.1 μm at the rotational speed of 120,000 min-¹ (2 kHz).