US Patent 11781451 Engine variable camshaft timing phaser with planetary gear set

An engine variable camshaft timing (VCT) phaser assembly is equipped in an internal combustion engine (ICE) to adjust the rotation of the engine's camshaft relative to the engine's crankshaft. The adjustments advance and retard the opening and closing movements of the engine's intake and exhaust valves. An electric motor and a planetary gear set work together amid use of the VCT phaser assembly. The planetary gear set can include two or more ring gears, planet gears, and a sun gear. A backlash condition sometimes experienced in previous VCTs is minimized in the VCT phaser assembly by one or more springs that urge the planet gears into engagement with the ring gears.