Single screw Extruder Construction
Sheet production extruder stators are provided in the drive housing and each stator surrounds a cylindrical rotor and each cylindrical rotor is formed as an internally toothed gear ring which is connected with a respective connecting shaft of a respective worm or screw. In this case, the worms can be driven in the same or opposite senses depending upon the sense of rotation of the respective rotor and intervening gear elements between the toothed shaft of each worm and the respective rotor are unnecessary.
In a second embodiment with reference to this mode of twin screw extruder, at least one cylindrical rotor is connected by an intervening element with the connection shaft of the associated worm or screw. Preferably, however, both cylindrical rotors can be connected by an intermediate element with connection shafts of the respective worm or screw. Advantageously one cylindrical rotor is connected directly with an intermediate shaft and the intermediate shaft is in turn connected with the connection shaft of the respective worms or screws. Preferably the intervening shaft carries a first gear which meshes with a second gear arranged on the respective connection shaft. The resulting gear connections or gear trains can be offset from one another longitudinally or transversely in the drive housing to provide a highly space-saving arrangement. With the system of the invention, therefore, the worms or screws can be driven in the same sense or in opposite senses in a particularly convenient and simple manner.
Two cylindrical stators are provided in the drive housing and each stator surrounds a cylindrical rotor. Each of the cylindrical rotors is connected with the connection shaft of one of the two worms or screws. According to a first embodiment of this mode of the invention, each of the cylindrical rotors is directly connected with the connection shaft of the associated worm or screw.
The invention is based upon the fact that single screw extruder can have a relatively simple construction and, especially, can be driven in a compact manner. All of the systems required for imparting torque to the screw or worm and/or controlling the direction of displacement is located within the housing. The fact that the rotor and stator lie in a common plane and that the connection of the shaft to the rotor is likewise in that plane contributes to the compactness of the system. The invention eliminates the need for complex transmissions, distributing gearing and the like and, of course, the maintenance associated therewith.