Split ring gear planetary cam phaser

A method for assembling and dynamically adjusting a rotational relationship of a camshaft (24) of an internal combustion engine with respect to an engine crank shaft comprising:

• assembling a planetary gear system (12) having a split ring gear (18) including a drive-side ring gear (18a) to be driven by the engine crank shaft through a sprocket (22) engaging an endless loop power transmission member and an output-side ring gear (18b) connectable for rotation with the camshaft (24);
• locating a sun gear (14) of the planetary gear system (12) concentric with respect to the split ring gear (18);
• engaging a number of planetary gears (16a, 16b, 16c) in meshing engagement between the sun gear (14) and the split ring gear (18);
• and
• providing the output-side ring gear (18b) with a different number of teeth compared with the drive-side ring gear (18a) by a value corresponding to a multiple of the number of planetary gears (16a, 16b, 16c) to provide tooth alignment at an engagement position of each of the planetary gears (16a, 16b, 16c).