SCREW DEVICE AND METHOD OF MANUFACTURING THE SAME

摘要

A screw device so designed as to receive a large load in one axial direction of a screw shaft and receive only a small load in the opposite direction. The screw device comprises the screw shaft (1) having a spiral ball rolling groove (1a) for rolling balls (7) formed in the outer peripheral surface thereof and a spiral roller rolling groove (1b) for rolling rollers (6) formed in the outer peripheral surface thereof, a nut (4) for balls having a spiral ball rolling groove (4a) facing the ball rolling groove (1a) of the screw shaft (1) formed in the inner peripheral surface thereof, a nut (5) for rollers having a spiral roller rolling groove (5a) facing the roller rolling groove (1b) of the screw shaft (1) formed in the inner peripheral surface thereof, the plurality of balls (7) arranged between the screw shaft (1) and the nut (4) for balls, and the plurality of rollers (6) arranged between the screw shaft (1) and the nut (5) for rollers. The nut (4) for balls and the nut (5) for rollers are connected to each other in the axial direction. Thus, the screw device enabling the easy control of a preload can be provided.