DRIVING APPARATUS FOR CASCADEETYPE EXTRUDER

摘要

Drive means for two screw extruders combined in a cascade arrangement wherein, instead of providing a drive motor and reduction gear for each screw, both screws are driven from the same drive motor and reduction gearing and a coupling gearing is included between the reduction gearing and one of the screws to enable different speed ratios of the two screws to be obtained. The coupling gearing may be shift gearing including pair of gears of different ratios alternatively and selectively included in the drive train to one of the screws by means of respective clutches. In another embodiment the coupling gearing includes a planet gearing with a ring gear of the planet gearing drivable by an electric motor to vary the speed of an output gear coupled to planet wheels compared to the speed of an input sun gear driven from the reduction gearing. A further embodiment has the planet gears connected to an output shaft, a ring gear connecting the planet gearing to the reduction gear and the sun gear connected to control gearing powered from the reduction gearing and controllable to vary the speed of the output shaft.