DE2051885A1 - Duplex worn screw extruder - allowing transverse adjustment of screw of screw journals and walls for careful plasticising of different mat - Google Patents

Abstract

The extruder, capable of carfully plasticising different synthetic thermoplastic materials at optimal output, has one or both of the worm screws mounted for radial adjustment to set the operating conditions, the adjustment being effected by transverse displacement of a respective bearing of a screw along a pair of guide rods. Screws are connected to drive shafts by universal shafts.

Description

Performing the plasticization of thermoplastic races i @ Mehrschnecken - 2051885 Eytrudern.

The invention relates to a device for gentle @ lastifi @ jerung of thermoplastic masses or the like.

in multi-screw extruders, in particular Deppel screw eytruders.

Several types of twin-screw extruders are known Screw spacing is characteristic for a given screw diameter. Essential feature of the twin screws for the gentle plasticization of thermoplastics Mass is the distance between the teeth of the two screws in connection with the screw diameter and the screw speed. For each recipe we have an optimal comb spacing for the maximum possible speed of the screws is required, but this is with the usual It is not always necessary to use snails different snails.

For this reason, changes to the recipe and the process technology are often necessary or even lower machine outputs can be accepted.

It is also known to have entire upper parts of the extruder, including the two Replace pinion shafts and the axial and radial bearings with other parts, to change the axis of the double shafts z. Such an Aust @@ ser Irit; in the buying production is very costly.

@@ Gerdem, the center distances can only be adjusted in stages. the The development of process engineering forces ever greater mobility with minimal Costs @ and.

There is another difficulty with the I) Opjelschi1ecken extruders in that the Schneekenachs distance determines the center distance in the transmission. Through this the two pinions themselves cannot be designed to be strong enough.

An excessively long ritual can therefore not lead to success, because the shafts are different because of the transfer of the entire torque twist. As a result, the tooth flanks of the inevitably twist one sprocket more than that of the other sprocket. The teeth have so over the entire length no more contact.

The frequent failures of the extruders in production therefore make new solutions required. For example, a transfer case has been developed in which half of the torque is distributed between the shafts and half on the worm shafts is transmitted. This makes the gearbox more complicated, but the two pinions can be executed stronger.

Another development is the use of conical screws. Here, both the pinion and the thrust bearing can be made larger.

The inventor has now set himself the task of both the problem the comb clearance and center distance adjustment to the respective thermoplastic mixture or the like. To solve as well as the previous mechanical deficiencies in the gear dimensioning to fix. This object is achieved essentially in such a way that with twin-screw extruders the position of the screws in relation to each other can be changed continuously, i.e. without replacement the gear elements have an axial bearing, can be transversely displaced on guide rods, the end taken out the actual gear and the shaft in question by means of a Propeller shaft is coupled to the transmission shaft. The second transmission time can also be used connect it to the worm Verkindeny through a cardan shaft, this cardan shaft with the second axial bearing, also removed from the gearbox is transversely displaceable.

An exemplary embodiment of the invention is shown in the drawing namely time: FIG. 1 - a schematic plan view of the device according to the invention.

FIG. 2 - the section A - B through FIG. 1 FIG. 3 - an addition to FIG.2 The axial bearing (a) is taken out of the gear (b) and transversely can be moved to the screw axes (c1) and (c2) on guides (d1) and (d2). Between A cardan shaft (e) is inserted in the axial bearing (a) and the gear shaft (b1). The axial forces on the worm axis (e1) are absorbed in the axial bearing (a) and only the torque is transmitted to the gear shaft (b1) via the cardan shaft (e). The two transmission shafts (b1) and (b9) can therefore have a considerably larger one Have center distance, whereby the size of both, pinions (b3) and (b4) no longer is limited. Furthermore, the problem of the axial bearing has been solved because the in the axial bearing (a), known tandem bearings with a few handles are interchangeable. The gearbox (b) therefore does not need to be dismantled.

The part of the device described so far enables the stepless Transverse movement of one of the screw axes (c1) or (c2). It would just have to be the Cylinder must be replaced. Therefore, the Zylin according to the invention is der Konstruktion (FIG.2) designed accordingly. The barrel of the extruder consists of the parts (f1), (f2) and (f3). When changing the center distance, the part (f3) is either shifted outwards or inwards. With relatively deep twin screws is dAitese soldering n the slight change in center distance of a few millimeters sufficient. The greater play resulting in the crest areas (g1) and (g2) leads even an excellent mixing effect. With twin screws with a relatively large Center distance, d., H. with a small thread depth, the construction according to FIG. 3 is used. The cylinder consists e.g. essentially made up of six parts. IT becomes through pretense of parts (f3) and (f4) the center distance increased or decreased, while the Parts (f5) and (f6) are used to correct the comb area.

With the device according to the invention, both the center distance the screws as well as the comb spacing steplessly to the respective thermoplastic or Like. Be adjusted. Contrary to the previously known statements, the problems the power transmission is solved by pinions that are no longer limited in terms of dimensioning. By removing the axial bearing from the gearbox, it can, contrary to all previously known designs, in the event of damage without dismantling the gearbox in can be replaced in a short time.

Claims (2)

P a t e n t a n s p r ü c h e: 1) Device for the gentle plasticization of thermonlastic Masses or the like in multi-screw extruders, plastic masses or the like in multi-screw extruders, in particular Donnel screw extruders, characterized in that the days of the Screws to one another is continuously variable in that the one axial bearing (a), on guide rods (d1) and (d2), non-displaceable, from the actual gear (b) taken out and with one gear shaft (b1) by means of a cardan shaft (e) is coupled. 2) Device according to claim 1, characterized in that the second Gear shaft (b2) also by a cardan shaft with the second, also from the axial bearing removed from the gearbox is connected. 3j device according to claim 1 and 2 with a multi-part extruder cylinder, as a result, it shows that if the screw axis distance is changed on one side the part (f3) or, if the screw axis distance changes on both sides, the Parts (f3) and (£ *), in the barrel of the extruder either outwards or inwards are movable. L e r s e i t e