Autotensioner

摘要

An autotensioner having a fixed shaft, a pulley support pivotally supported on the fixed shaft, a pulley rotatably supported on the pulley support and a spring for biasing the pulley support in such a direction as to apply tension to a belt. The pulley support has a cylindrical portion arranged coaxially with the fixed shaft. The fixed shaft is formed with cam surfaces at such a position that wedge-shaped spaces are defined between the cam surfaces and the cylindrical portion. The wedge-shaped spaces narrow in a direction in which the pulley support pivots to slacken the belt. Friction members are each mounted in the respective wedge-shaped spaces. They have a shape substantially complementary to the shape of the wedge-shaped spaces. A spring member is also mounted in each wedge-shaped space to bias the friction members into the narrow area of each wedge-shaped space.