... 5.long service life SZ Conical twin-screw gear box1.General SurveySZ serial gearbox for Conical ... is a special driving unit matached with conical twin-screw rod extruder. It consists of two parts,namely, ... included angle is the same with that of twin-screw rods) via a pair of small conical gears with ... driving ration of 1:1, thus to drive screw rods to rotate outward with different direction.2.Features Of ...