Device for changing the control times of gas exchange valves in an internal combustion engine, in particular, a rotating piston adjustment device for angular adjustment of a camshaft relative to a crankshaft

A device for changing the control times of gas-exchange valves in an internal combustion engine is provided, which includes a drive wheel ( 2 ) in driven connection with the crankshaft and a vane rotor ( 3 ) fixed with the camshaft. The drive wheel ( 2 ) has a hollow space, which is formed by a hollow cylindrical peripheral wall ( 4 ) and two lateral walls ( 5, 6 ), in which at least one hydraulic work chamber ( 9 ) is formed by at least two radial limit walls ( 7, 8 ), which is divided by at least one vane ( 11 ) into an A pressure chamber ( 12 ) and a B pressure chamber ( 13 ). The vane rotor ( 3 ) can be coupled mechanically with the drive wheel ( 2 ) by a separate locking element ( 14 ), that can be moved into a locked position within a receptacle ( 19 ) in the lateral walls ( 5 ) of the drive wheel ( 2 ). The receptacle ( 19 ) is connected hydraulically to the A pressure chamber ( 12 ) via a pressure medium supply groove ( 18 ) provided in an inner surface of the lateral wall ( 5 ), so that upon pressurization of the A pressure chamber ( 12 ), the locking element ( 14 ) can move hydraulically into an unlocked position in the rotor hub ( 10 ) of the vane rotor ( 3 ). According to the invention, a local stop ( 20 ) is arranged within the pressure medium supply groove ( 18 ) in the inner surface of the lateral wall ( 5 ), through which a pressure medium supply to the receptacle ( 19 ) of the locking element ( 14 ) is possible only through a bypass ( 21 ) when the vane rotor ( 3 ) is in the base position.