YPS series gearbox is a standard driving part designed and developed for counter-rotating parallel twin screw extruder. Its gear is made of low carbon alloy steel by carbon penetrating, quench and teeth grinding to reach high strength and precision. The output shaft is finely made of special alloy steel to suit the requirement of large output torque. The thrust bearing group is a combination design that adopts advanced tandem thrust cylindrical roller bearing and full complement cylindrical roller bearings which have a large bearing capacity. The lubrication style adopts oil immersion and spray lubrication and it can also be equipped with pipe style cooling system based on the different requirements of the machine. The whole machine has a well-balanced appearance，advanced structure，superior bearing performance and smooth operation. It is an ideal selection of counter-rotating parallel twin screw extruder gearbox.