Tensioner for a traction drive

A tensioner for a traction drive to maintain a belt under tension includes a base part and a pivot arm connected to the base part for swinging about a rotation axis and having a free end for rotatable arrangement of a roller which is supported on the power transmitting member. A torsion spring acts on the pivot arm for urging the roller against the belt and applies an axial force on a damping unit for damping an adjusting movement of the pivot arm. The damping unit includes a slitted friction bushing constructed to have a wedge ring with conical inner and outer surfaces for formfitting engagement in a circular ring shaped recess of the base part or the pivot arm. The recess has contact surfaces to complement the inner and outer surfaces of the friction bushing for formation of two conical contact zones.