Sheet production extruder transmission
A twin screw extruder drive has a housing, at least two extrusion worms each having a drive shaft extending into the housing, and at least one drive motor including at least one cylindrical stator fixed in the housing and a cylindrical rotor cooperating with the stator so as to be rotatably driven by the stator. The rotor surrounds the drive shafts, and each of the drive shafts is independently connected to the rotor for driving thereby.
A double-worm or double-screw extruders has a housing with at least two compartments extending over its length and a drive at an end of the housing for rotating the screws or worms in the same or opposite senses. The screws are rotatable in the respective chambers of the extruder housing and have their flights intercalated so that they subject a synthetic-resin mass to plastification and liquefication. The extruder also pressurizes the thermoperiodism mass so as to force the synthetic resin material through an extrusion die or into a mold.
An single screw extruder drive assembly comprising: a housing; at least two extrusion worms each having a drive shaft extending into the housing; and at least one drive motor including at least one cylindrical stator fixed in the housing and a cylindrical rotor cooperating with the stator so as to be rotatably driven by the stator, the rotor surrounding the drive shafts, each of the drive shafts being independently connected to the rotor for driving thereby.
The drive housing has a mechanism for rotating the worms or screws and the principles described are applicable not only to two-worm extruders but also extruders having more than two worms. It is common to provide so-called double-worm or double-screw extruders with a drive motor which is coupled to the two worms or screws. For example, the extruder screws can be connected by means of a transmission with the drive motor. depending on the type of drive or transmission used, the double-screw extruder can be relatively bulky. In addition, the transmission or drive may be subject to failure and the maintenance thereof can be comparatively expensive.
In one system, each of the screws or worms with a sheet production extruder can be separately driven by a respective drive motor and corresponding transmission. To achieve synchronism between the two extruder screws, the two drives can be coupled with one another. This arrangement also is quite voluminous and there always may be problems with the reliability of the synchronism system. In addition, such double-screw extruders are comparatively expensive.