ARTICULATION DRIVE ASSEMBLIES FOR SURGICAL INSTRUMENTS SUCH AS FOR USE IN SURGICAL ROBOTIC SYSTEMS

An articulation assembly for a surgical instrument includes a proximal housing including a central cylindrical body four internal cavities arranged about the central cylindrical body. First and second coupling gears are coaxially disposed about the central cylindrical body and positions distally and proximally, respectively. First and second input shafts are disposed at least partially within the first and second cavities, are configured to receive first and second rotational inputs, and include respective first and second gears disposed in meshed engagement with the first and second coupling gears, respectively. Four output gears are disposed within the four cavities; two are disposed in meshed engagement with the first coupling gear and two are disposed in meshed engagement with the second coupling gear.