Tensioning device for belts

摘要

In a tensioning device for belts, chains or the like, especially for the camshaft drive of an internal combustion engine, with a tensioning pulley (5) which is mounted on a movable support (4) and with a control element (8) by means of which the support can be moved by way of an actuating member in the direction of relaxation of the belt, counter to the action of a compression spring (14), when the temperature rises, the control element (8) is formed by a hollow-cylindrical sleeve (11) and a pressure piston (9) which can be displaced longitudinally therein and on that part of which which is situated outside the sleeve (11) a pressure piece (7) is rotatably placed and held in a manner free from axial play, this pressure piece having a flat, oblique contact surface which forms an acute angle with the axis of the piston and rests in contact with a corresponding contact surface (6) of the support of the tensioning pulley (5). <IMAGE>