| 摘要 |
Provided is a tensioner for suppressing retraction of the appearing margin position of a propulsion member and spring fatigue fracturing which occur over time, and preventing output loss due to excessive tension. A tensioner (1) is accommodated in a case (5) with a rotating member (3) and a propulsion member (2) threaded together by a screw part (6), the rotating member (3) is rotatably urged by the torque of a spring (4), the propulsion member (2) is made to reciprocate relative to the case (5) by the rotation of the rotating member (3), and one end surface of the rotating member (3) slides over a receiving surface (7) of the case (5), whereby sliding resistance is created between the rotating member (3) and the receiving surface (7) along with the rotation of the rotating member (3). The sliding resistance during rotation of the rotating member (3) in a first rotation direction (11), corresponding to the retraction of the propulsion member (2), is set to be great enough to suppress the rotation of the rotating member (3) in the same direction (11), and the sliding resistance during rotation of the rotating member (3) in a second rotation direction (12), corresponding to the advancing of the propulsion member (2), is set to be great enough to suppress the rotation of the rotating member (3) in the same direction (12). |
