Valve drive arrangement

A valve drive arrangement for an internal combustion engine including a first camshaft unit which comprises an outer shaft with primary cams connected to the outer shaft, a second camshaft unit which comprises an inner shaft disposed in the outer shaft and having secondary cams movably disposed on the outer shaft but connected to the inner shaft for movement with the inner shaft relative to the outer shaft and an adjusting unit disposed on the outer shaft and also connected to the inner shaft for adjusting the axial position of the two camshaft units relative to each other, the inner shaft comprising at least two shaft elements which are arranged axially adjacent one another and interconnected by an axial slide coupling (P′) for common rotation but axial displacement in sequence, one after the other, during a switching process, and the inner shaft being furthermore rotatable relative to the outer shaft together with the secondary cams supported on the outer shaft for an adjustment of the phase angle between the primary cams mounted on the outer shaft and the secondary cams rotatably supported on the outer shaft but connected, by connecting elements, to the inner shaft elements for rotation and axial movement therewith.