A Transition Curve-Based Design Method for the Recirculation Channel in Internal Recirculating Ball Screws

<div>Internal recirculating ball screws are widely used as linear motion components in automotive active safety systems, owing to their simple structure and compact size. The recirculation (or deflection) channel is a key feature that distinguishes this type from other ball screw designs. The objective of this article is to investigate this key feature that has been rarely addressed in existing research on internal ball screw. The conventional design method for the recirculation channel involves sweeping the cross-section along the center curve. The center curve is typically defined by various classical equations. These equations are applied in different application scenarios. In automotive braking systems, high loads and strict size constraints place critical demands on both the recirculation channel and its center curve. As a representative best-practice example, the machined channel in the screw is typically employed in this application. This article compares several classical center curve equations and proposes a new general approach based on a family of transition curves. The mechanical analysis identifies the inherent structural characteristics of recirculation channel and develops corresponding design guideline. Furthermore, parameter optimization is performed using MSC ADAMS Multibody Dynamics (MBD) software.</div>