UNIAXIAL ACTUATOR

PROBLEM TO BE SOLVED: To provide a uniaxial actuator in which frictional resistance caused by movement of a movable body and spacer plates is small and which allows a gap between a cover body and a storage body to be closed stably.SOLUTION: A ball screw 1 is stored in the rectangular storage body 2, the movable body 4 is attached to a ball nut 3 which is screwed to the ball screw 1, the open surface of the longitudinal lateral surface of the storage body 2 is covered with the cover body 6, the spacer plates 7 of the movable body 4 are protruded from adjacent both lateral surfaces of the open surface of the storage body 2 to the longitudinal lateral side, the gap which is formed between the cover body 6 and the storage body 2, and makes the spacer plate 7 move therethrough is covered with a belt-like seal member 8, the seal member 8 is guided to the protruded outer lateral surface of the spacer plate 7 by using a roller 10 attached to the spacer plate 7 of the movable body 4, thereby, the frictional resistance is reduced, the seal member 8 is not permanently deformed and, therefore, the gap between the cover body 6 and the storage body 2 can be stably closed.