Patent ID: 6089117
Filing Date: 2000-07-18
Classification: F16C,F16H,Y10T

Abstract:
A ball screw unit provided with a screw having a helical ball rolling groove on the outer peripheral surface thereof, a nut assembly having a load zone comprising a helical load rolling groove opposing to the helical ball rolling groove of the screw and a no-load zone forming a ball endless track by establishing communication between a starting end and a terminating end of the load zone, a number of balls rolling within the ball endless track of the nut assembly and a ball coupler comprising a plurality of coupling members capable of retaining the balls in their rotatably aligned state, wherein a guide groove for guiding the coupling members of the ball coupler is formed in the no-load zone of the ball endless track such that the coupling members are moved by the balls in the load zone of the ball endless track while the balls are guided to move by the coupling members in the no-load zone of the endless track, and guide sections for guiding the coupling members along the progressing direction of the balls moving in the load zone are respectively provided at least at both ends of the no-load zone lying near the load zone.