Camshaft assembly

In combination, a camshaft assembly and a phaser for connecting the camshaft assembly to an engine crankshaft, wherein the camshaft assembly comprises

• an inner shaft,
• an outer tube surrounding and rotatable relative to the inner shaft,
• a first group of cam lobes mounted on the outer tube and fast in rotation with the outer tube,
• a second group of cam lobes rotatably mounted on the outer surface of the tube,
• circumferentially extending slots in the outer tube,
• pins projecting from the inner shaft and passing with clearance through the circumferentially extending slots in the outer tube to engage and drive the second group of cam lobes, and
• a sleeve rotatably mounted on the outer tube, the sleeve being connected to impart drive to the inner shaft by means of a pin passing with clearance through a circumferentially extending slot in the outer tube, and
• wherein the phaser has concentric inner and outer output elements connected to the camshaft assembly to enable the phase of the inner shaft and outer tube of the camshaft assembly to be varied dynamically relative one another, the inner shaft of the camshaft assembly being coupled to outer output element of the phaser by way of the sleeve.