In the past, many papers have studied the structural optimization of servo motors from a motor's design viewpoint, but very few have reported the interrelation between a servo motor's specifications and the feed axes of machine tools. In this paper, the interrelation between a servo motor's specifications and the dynamic performance of feed axes of machining centers selected as a representative of machine tools is studied.
First, among the servo motor specifications the moment of inertia affecting dynamic performance of machine feed axes is especially focused, and the moment of inertia ratio of a machine feed axis to a servo motor is investigated by a mechanical model. Next, machining centers used in actual machining field and servo motors installed in them were researched, and the interrelation between the kind of the machining center and the moment of inertia ratio is analyzed.
As a result, the actual field examples confirm the validity of the investigation by a mechanical model. In short, servo motors with relatively low moment of inertia are suited to machining centers targeting high cycle machining, while those with relatively high moment of inertia are suited to machining centers targeting high precision and fine surface machining.