| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball screw device which can surely prevent the lock of a ball screw device irrespective of a length of a non-circulation passage while enabling short-time processing by tag processing.SOLUTION: In a ball screw device having a plurality of circuits, a screw shaft formed with a spiral screw groove and a penetration hole for allowing the passage of the screw shaft are arranged at an external peripheral face, a spiral nut groove 13c constituting a plurality of rolling routes in which a plurality of balls roll is formed at an internal peripheral face of the penetration hole together with the screw groove, a nut 13 screwed to the screw shaft via the balls and a plurality of tops fixed to the nut are arranged, a plurality of the tops constitute a return route for connecting both ends of the rolling routes at an internal peripheral face of the nut 13, and the circuits for infinitely circulating the balls are constituted together with the rolling routes. An escape groove 13d which is connected to the nut groove 13, and deeper than the nut groove is formed at a portion of a nut internal peripheral face which is located between a plurality of the circuits in an axial direction. |
