Drive device for a twin-screw extruder which is drivable for rotation in the same direction, the drive device comprising - a superimposition gear drive (6; 6a; 6b) for superimposing the driving powers of two different drive motors (2, 3), the superimposition gear drive (6; 6a; 6b) comprising -- two superimposition gear drive input shafts (8, 10) which are drivable for rotation by the two different drive motors (2, 3); and -- a superimposition gear drive output shaft; - a power splitting gear drive (7; 7c, 7f; 7g; 7h) for splitting the driving powers which have been superimposed at the superimposition gear output shaft, the power splitting gear drive (7; 7c, 7f; 7g; 7h) comprising two power splitting gear drive output shafts (42, 43; 42f, 43f; 42g, 43g; 42h, 43h) which are couplable to two screw shafts (52, 53) of a twin-screw extruder, characterized in that the superimposition gear drive (6; 6a; 6b) is a differential superimposition gear drive, the differential superimposition gear drive (6; 6a; 6b) comprising: - a differential cage (15; 15a; 15b); - a bevel gear which is mounted to the differential cage (15; 15a; 15b) for rotation about a first axis of rotation; - a second bevel gear which is arranged opposite to the first bevel gear and is mounted to the differential cage (15; 15a; 15b) for rotation about the first axis of rotation; and - at least three superimposition bevel gears -- which are mounted to the differential cage (15; 15a; 15b) for rotation about respective second axes of rotation, with the second axes of rotation being perpendicular to the first axis of rotation; -- which couple the first bevel gear with the second bevel gear; and -- which are arranged rotationally symmetrical about the first axis of rotation; - a gear which is coupled to the differential cage (15; 15a; 15b). - a superimposition gear drive (6; 6a; 6b) for superimposing the driving powers of two different drive motors (2, 3), the superimposition gear drive (6; 6a; 6b) comprising -- two superimposition gear drive input shafts (8, 10) which are drivable for rotation by the two different drive motors (2, 3); and -- a superimposition gear drive output shaft; -- two superimposition gear drive input shafts (8, 10) which are drivable for rotation by the two different drive motors (2, 3); and -- a superimposition gear drive output shaft; - a power splitting gear drive (7; 7c, 7f; 7g; 7h) for splitting the driving powers which have been superimposed at the superimposition gear output shaft, the power splitting gear drive (7; 7c, 7f; 7g; 7h) comprising two power splitting gear drive output shafts (42, 43; 42f, 43f; 42g, 43g; 42h, 43h) which are couplable to two screw shafts (52, 53) of a twin-screw extruder, - a differential cage (15; 15a; 15b); - a bevel gear which is mounted to the differential cage (15; 15a; 15b) for rotation about a first axis of rotation; - a second bevel gear which is arranged opposite to the first bevel gear and is mounted to the differential cage (15; 15a; 15b) for rotation about the first axis of rotation; and - at least three superimposition bevel gears -- which are mounted to the differential cage (15; 15a; 15b) for rotation about respective second axes of rotation, with the second axes of rotation being perpendicular to the first axis of rotation; -- which couple the first bevel gear with the second bevel gear; and -- which are arranged rotationally symmetrical about the first axis of rotation; -- which are mounted to the differential cage (15; 15a; 15b) for rotation about respective second axes of rotation, with the second axes of rotation being perpendicular to the first axis of rotation; -- which couple the first bevel gear with the second bevel gear; and -- which are arranged rotationally symmetrical about the first axis of rotation; - a gear which is coupled to the differential cage (15; 15a; 15b).