Ball screw drives with enhanced bandwidth by modification of the axial bearing

The bandwidth of the ball-screw drive is limited by the first natural frequency of the mechanical structure. As opposed to conventional drives where the axial bearing stiffness is kept high to obtain higher natural frequencies, this paper proposes to use lower axial bearing stiffness accompanied by a strong damper in parallel with the ball-screw structure. The proposed method, which is experimentally demonstrated, increases the bandwidth of the drive considerably provided that a cost effective and practical damper is available.