Ball screw mechanism

Abstract

The invention provides a ball screw mechanism including a screw having a first axis and at least one screw groove extending along a first helical path about the first axis. The ball screw mechanism also includes a nut having a first aperture receiving the screw. The nut also includes at least one nut groove extending along a second helical path about the first axis between first and second edges disposed on opposite sides of the screw. The at least one screw groove and the at least one nut groove are aligned and cooperate to form a helical passageway extending at least 180 degrees about the first axis between a first opening at the first edge and a second opening at the second edge. The ball screw mechanism also includes a plurality of balls moving, in part, along the helical passageway. The ball screw mechanism also includes a external ball nut return radially spaced from the screw extending at least partially around the nut between a third opening communicating with the first opening and a fourth opening communicating with the second opening to circulate the plurality of balls with respect to the helical passageway.

Dependencies are inferred from the claim text.