Hydraulic tensioning device for especially timing chain of internal combustion engine has pressure chamber ventilation device with cap pressurized by spring unit onto base of recess in pressure chamber

摘要

The hydraulic tensioning device for an endless drive element has a tensioning piston (4) guided in a pressure chamber (6) which has a ventilation device with a cap (14) pressurized by a spring unit onto the base (16) of a recess in the pressure chamber. The circumferential surface (23) of the cap with the recess wall encompassing it forms a restrictor (19). A channel (21) is formed between the base surface of the recess and end face (15) of the cap, and through this the restrictor is connected to a ventilation hole (25) in the tensioning piston.