<p>A higher efficiency roller screw system (10) that includes a nut body (12) designed to engage a threaded shaft (70). The nut body (12) includes a center bore (15) with closed, partial helical grooves (20) formed therein. Disposed inside the center bore (15) is a shaft (70) with open helical threads (72) formed thereon. A plurality of rollers (34) with non-helical grooves (35) formed thereon are also disposed inside the nut body's center bore (15) and longitudinally alligned with the shaft (70) the grooves (35) on each roller (30) are designed to engage the grooves (20) on the nut body (12) and the threads on the shaft. The nut body (12) includes a cross-over region (40) where the trajectory of the internal grooves (20) extend radially outward and axially. When the roller's grooves (35) contact the grooves (42) in the cross-over region (40), the rollers (34) are forced outward to maitain contact with the grooves (20) on the nut body (12) and are defleted axially. When they move outward, they disengage from the helical threads (72) on the shaft (70). As the nut body (12) continues to rotate, the grooves (35) on the rollers (34) maintain contact with the grooves (20) on the nut body (12) and re-engage the helical threads (72) on the shaft (70).</p>
