Traction tensioner for use in clamping apparatus for traction drive, has ventilation contour connected with through-hole and inserted in outer surface of front end of piston, where through-hole is formed at outer surface

摘要

The tensioner has a housing (3) pressurized to push a hollow and lengthwise-movably mounted piston (2). The piston abuts against a pressing portion (4) of a tensioning rail (5) to stretch a traction unit extending over the piston. A front end (6) of the piston is turned toward the pressing portion. A through-hole is formed at an outer surface of the front end of the piston and connects a cavity formed in the piston with an external environment of the piston. A ventilation contour (10) e.g. groove or recess, connected with the through-hole is inserted in the outer surface.