Device for changing the control timing of the gas exchange valves of an internal combustion engine, in particular a hydraulic camshaft adjustment device of the rotary piston type

Abstract

A hydraulic camshaft-adjusting device of the rotary piston type having a drive gear ( ) and an impeller. The drive gear ( ) has a cavity formed from a perimeter wall and two side walls ( ) inside of which at least one hydraulic working chamber is formed from at least two boundary walls ( ). The impeller has a wheel hub ( ) with at least one vane that extends into a working chamber, dividing the chamber into two associated hydraulic pressure chambers. The pressure medium feed to and from the pressure chambers is done using a pressure medium tap ( ) on the side facing a camshaft as well as using pressure medium channels ( ) incorporated into the axial sides ( ) of the wheel hub ( ) of the impeller, which are connected to the pressure medium tap through a pressure medium distributor ( ). The pressure medium tap ( ) and the pressure medium distributor ( ) are encircled at the head ( ) and the outer surface ( ) by a respective penetration ( ) in the side walls ( ) of the drive gear ( ). The gaps between the head ( ) of the pressure medium distributor ( ) at the penetration ( ) of the one side wall ( ) of the drive gear ( ) and between the outer surface ( ) of the pressure medium tap ( ) and the penetration ( ) at the other side wall ( ) of the drive gear ( ) are sealed off through wear-resistant sealing media against pressure medium leakage