| 摘要 |
Rotary motion of a ball screw (36) is converted by a feed nut (60) into rectilinear motion to allow a displacement mechanism (38) to make rectilinear motion. When the ball screw (36) involves axial deviation, then an engagement member (68) slides in a direction of the arrow C with respect to a nut holder (64) by the aid of a first guide mechanism (72), and a second sliding guide (76) slides in a direction of the arrow B with respect to the engagement member (68) by the aid of a second guide mechanism (80). Accordingly, even when the ball screw (36) involves axial deviation with respect to the second sliding guide (76), the sliding resistance is not increased between the second sliding guide (76) and a frame (32) of an actuator (30). Therefore, even when there is any axial deviation between the ball screw (36) and the frame (32), there is no fear of obstructing the displacement action of a displacement member (84). <IMAGE> |
