Universal driving device

A universal driving device comprising:

• a ring gear;
• a sun gear having a sun gear axis is moveable relative to a ring gear axis of the ring gear;
• a gear train comprising a series of gears configured to connect the sun gear and the ring gear;
• a plurality of link mechanisms configured to accommodate a change in an inter-axis distance between the sun gear and the ring gear, and rotatably connected with respect to each other to continuously maintain a power transmission state between the sun gear and the ring gear, thereby supporting rotation shafts of gears constituting the gear train;
• a carrier configured to support a rotation shaft of a final gear engaged with the ring gear, among the gears constituting the gear train;
• a sun gear bearing positioned between the rotation shaft of the sun gear and each of the plurality of link mechanisms;
• and
• a sleeve positioned between the sun gear bearing and each of the plurality of link mechanisms.