Patent attributes
An electric phaser dynamically adjusting the rotational relationship of a camshaft of an internal combustion engine with respect to an engine crankshaft includes an electric motor and a planetary drive. In some embodiments, the planetary drive includes a sun gear, planet gears, a sprocket ring gear driven by the engine crankshaft, a camshaft ring gear rotating with the camshaft, a carrier, a lever arm, and a load generator. The lever arm is rotatably attached to at least one planet gear and pivotably attached to the carrier at a pivot point on the carrier located off-axis from the sun axis. The load generator is coupled to the carrier and applies a torque load to the lever arm to reduce backlash in the split ring planetary drive. The difference between the number of camshaft ring gear teeth and sprocket ring gear teeth is a multiple of the number of planet gears.
