Tensioner for belt or chain pulleys esp. for use in motor vehicles

摘要

The tensioner has a one-piece guide plate (2) and support (3) forming a hollow hub, with an end plate (18) and a bolt for fixing the position of the rotation centre of the tensioning pulley (5) via an eccentric (11). The hub contains a torsion spring (16). The eccentric can rotate wrt. the support in response to sharp variations in belt tension but its movements are damped by the spring so as to minimise the loss of belt tension. The amount of tension in the belt is set using a tool which moves the eccentric against the spring to generate the tension required.