Device for changing the phase of a camshaft relative to a crankshaft of a combustion engine

The changing device (1) is provided with a drive element (4) propelled by a sprocket (3), where two hydraulic chambers are formed between the drive element and the camshaft (2). The hydraulic chambers are impinged with a compressed fluid. The sprocket forms a bearing surface (5) for the axial start of the cam shaft or a component.