Gearbox assembly for a twin-screw extruder, treatment installation for material treatment comprising a gearbox assembly of this type, and method for the startup of a treatment installation comprising a gearbox assembly of this type

A treatment installation for material treatment, comprising:

• a twin-screw extruder comprising two screw shafts;
• a gearbox assembly comprising a speed change gearbox for adjusting a screw shaft speed of the two screw shafts of the twin-screw extruder, a speed reduction gearbox and a distribution gearbox with two distribution gearbox output shafts allowing the screw shafts of the twin-screw extruder to be coupled thereto, wherein the speed change gearbox is arranged at a driving end, wherein the speed reduction gearbox couples the speed change gearbox to the distribution gearbox, wherein the speed reduction gearbox has precisely one speed reduction gearbox input shaft, the precisely one speed reduction gearbox input shaft having a first speed reduction gearbox gear and a speed reduction gearbox output shaft having a second speedreduction gearbox gear, the first speed reduction gearbox gear and the second speed reduction gearbox gear being in meshing engagement, wherein a speed change gearbox output shaft of the speed change gearbox gear is detachably connected to the speed reduction gearbox input shaft so that the speed change gearbox and the speed reduction gearbox are configured such as to be separable from each other, wherein a speed change gearbox housing of the speed change gearbox and a speed reduction gearbox housing of the speed reduction gearbox are configured such as to be separate from each other;
• and
• a drive motor coupled to the speed change gearbox.