Patent ID: 8122863

Claim:
A camshaft phaser assembly for a concentric camshaft that adjusts the relative rotational position of an inner camshaft relative to an outer camshaft and a crankshaft of an internal combustion engine, the phaser assembly comprising: an inner rotor with radially outwardly extending vanes which is attached to the inner camshaft; a stator having radially inwardly directed projections which contact the outer surface of the rotor and form working spaces into which the vanes extend, the vanes divide the working spaces into first and second sets of pressure chambers which can be pressurized with a hydraulic medium in order to rotate the rotor in an advancing or retarding direction; front and rear covers attached to the stator which define front and rear sides of the pressure chambers; a timing gear or timing belt pulley connected to the stator; and the rear cover includes a splined opening and a front end of the outer camshaft includes a splined connection complementary to the splined opening in order to provide a positive fit connection between the outer camshaft and the rear cover for direct transfer of the timing chain or belt loads into the outer camshaft.