TENSIONER

摘要

A tensioner capable of stably suppressing amplitude even for a strong input vibration load from an engine, the suppression being made over a wide range of engine speed both in advancing operation and retreating operation. A first shaft member (3) and a second shaft member (4) screwed to each other by screw portions (8, 9) and a return spring (5) for rotatingly urging the first shaft member (3) in one direction are received in a case (2). The second shaft member (4) is restrained from rotation, and a rotation urging force by the return spring (5) is converted into a propulsive force of the second shaft member (4). A resisting torque applying mechanism (20) is placed between the first shaft member (3) and the second shaft member (4), and the mechanism constantly produces, both in advancing operation and retreating operation, resisting torque against an external input load inputted in the second shaft member (4), finely and stably suppressing the amplitude of the second shaft member (4).