| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent generation of a moving defective of a ball by disposing a freely movable ball along a ball rolling surface of a screw shaft on a nut member onto which the revolved and driven screw shaft is screwed and holding this ball so that the ball may not move and may rotate for the nut member. SOLUTION: An actuator to be used as a carrier device of a work has a ball screw 34 to be rotated by a motor and a nut member 36 onto which this ball screw 34 is screwed and which moves in the direction of the arrow A for the ball screw 34. In this nut member 36, a freely slidable ball 40 is disposed along a ball rolling surface 38 of the ball screw 34 and this ball 40 is held by a holding means 42 so that the ball may not move and may rotate for the nut member 36. The holding means 42 is provided with an oil supply means 56 for performing fluid lubrication and elastic fluid lubrication between each recessed part 54 and the ball 40. On an inner peripheral surface 52 of the nut member 36, a ring-shaped groove part 68 is formed and a scraper 70 is fixed to this groove part 68. |
