| 摘要 |
PROBLEM TO BE SOLVED: To make a joint part using a direct-acting actuator into a waterproof structure.SOLUTION: Both ends of a screw shaft 10 forming a direct-acting actuator are fixed, the screw shaft is driven by a motor that is also fixed to a frame, via a gear or a timing belt and a rod is fitted to a ball screw nut as an only movable part. As a mechanism for supporting an external force from the movable part. Four rollers are provided in a nut holder and moved between upper and lower roller guides that are disposed in parallel with a ball screw, such that a screw part is prevented from being damaged by tilting the ball screw nut. In such a structure, the movable part rod is formed in a round shaft shape, an oil seal is passed through the shaft, and the oil seal is supported by a holder guide that extends from a position of a tilt center of the movable part. Thus, a position of the oil seal is prevented from being unfixed with elongation/contraction of the shaft, and a rubber boot 17 is mounted to an oil seal holder whose position is stabilized.SELECTED DRAWING: Figure 2 |
