Ball Screw Device

摘要

There is provided a ball screw device capable of allowing interference to be easily elastically deformable and decreasing friction resistance of a seal member with respect to a screw shaft without damaging seal properties of the seal member. A predetermined section of a land sliding-contact portion (46) of a sliding-contact portion (40) and a section of a seal piece (37) of a lip portion (31) corresponding to the predetermined section are bent to protrude in one side in the axial direction of a nut (7) so that a protrusion (55) is formed, the bent section of the land sliding-contact portion (46) and the bent section of the seal piece (37) configure a pair of side surface portions (58, 58) of the protrusion (55) and a bottom portion (61) connecting the one side ends of the pair of side surface portions (58, 58).

主权项

1. A ball screw device comprising:
a screw shaft linearly extending and including a helical rolling groove formed on an outer circumferential surface; a cylindrical nut including a rolling groove opposing the helical rolling groove on an inner circumferential surface, and screwed to the screw shaft via a plurality of balls which disposed between the rolling groove and the helical rolling groove of the screw shaft; balls disposed between track grooves formed of the rolling groove of the nut and the rolling groove of the screw shaft; an annular sealing device provided on an inner diameter side of the nut and sealing a gap between the nut and the screw shaft; and a tip portion of a lip portion externally fitted to the screw shaft and including an inner circumferential edge portion coming into sliding-contact with an outer circumferential surface of the screw shaft, wherein the tip portion of the lip portion includes an easily deformable portion elastically deformed so that a shape of the inner circumferential edge portion is matched to a shape of the outer circumferential surface of the screw shaft when the tip portion of the lip portion is assembled to the screw shaft.