Ball-screw rigidity is a matter of definition: Not all ball-screw makers spec products the same way

摘要

Stiffness or rigidity is a key factor in evaluating ball-screw drives for specific needs. Rigidity, in this context, describes a ball screw's elastic deformation under load and directly affects the precision of an axis drive, especially in machine tools. Unfortunately, not all screw manufacturers quantify rigidity based on DIN/ISO standards, which can cause confusion. Japanese manufacturers, for example, often use a theoretical "K-value" to describe stiffness, from which 20% is typically subtracted to get an actual value. Still other ball-screw makers don't specify which value is being used at all, and the numbers given may well be theoretical and therefore useless for purposes of application engineering.