Parallel counter-rotating intermeshing twin-screw extruder

Abstract

The invention discloses a parallel counter-rotating intermeshing twin-screw extruder used for compounding or compounding extrusion of plastic materials such as plastic. The parallel counter-rotating intermeshing twin-screw extruder comprises a parallel counter-rotating intermeshing twin-screw continuous extrusion device, a tail side transmission case, a head side transmission case, and at least one motor; the parallel counter-rotating intermeshing twin-screw continuous extrusion device comprises a combined type or an integral housing; the housing comprises two cavities which are parallel in longitudinal direction and are intercross along longitudinal direction; each cavity is provided with a pair of counter-rotating intermeshing screws, one of the counter-rotating intermeshing screws is protruded out of the head end and the tail end of the housing respectively, the forward protruded end is driven to rotate by the head side transmission case, and thrust supporting of the backward protruded end is realized by the tail side transmission case reelingly in longitudinal direction i.e. in axial direction; the other counter-rotating intermeshing screw is protruded out of the tail end of the housing, and thrust supporting and driving of the backward protruded end is realized by the tail side transmission case reelingly in longitudinal direction i.e. in axial direction, so that torque density (M / a<3>) is capable of exceeding 10Nm / cm<3> economically and serviceably, and is capable of exceeding 25Nm / cm<3> significantly.

Description

Technical field: [0001] The invention relates to an intermeshing twin-screw extruder for extruding plastic materials such as plastics, in particular to a parallel and counter-rotating intermeshing twin-screw continuous extrusion device for a high-torque parallel counter-rotating intermeshing twin-screw extruder and corresponding drive components. Background technique [0002] There are more than one type of intermeshing twin-screw extruder for extruding plastic and other plastic materials according to whether the two screws are parallel or not and the direction of rotation is the same or different. Parallel counter-rotating intermeshing twin-screw extruder (Parallel counter -rotating intermeshing twin-screw extruder) belongs to one of the more important categories at present. [0003] The parallel counter-rotating intermeshing twin-screw extruder for extrusion of plastic materials such as plastics has a parallel counter-rotating intermeshing twin-screw continuous extrusion ...

AI Technical Summary

Problems solved by technology

In fact, in order to ensure the uniform load of the gear teeth, the gear manufacturing needs to include the modification of the tooth direction and even the tooth profile, which can increase the cost by at least 3 times. Gear Manufacturers Association Standard) 10 and a half to 12 and a half or DIN (German Industrial Standard) 6 to 4 meshing precision, that is, gears, shafts, bearings and housings of corresponding precision levels are required to achieve, which is compared with the so-called "standard" Accuracy grade" is DIN 7 grade (corresponding to AGMA grade 9 and a half or China national standard grade 7), the cost of which is at least 3 times higher than that of the tail-side transmission box, which makes the high-torque traditional parallel counter-rotating intermeshing twin-screw extruder very expensive

[0054] Second, the driven gear on the shorter overhanging shaft itself is a high-load final gear, and the smaller pitch circle diameter causes its wear time life to be insufficient in the "one-to-one" gear transmission. Compared with "one-to-one" gear transmission, the "many-to-one" gear transmission, the number of gear teeth meshing per revolution, that is, the number of wear times is doubled (2-4 times), and the corresponding wear time is doubled (2-4 times) and the service life is shortened. , making the gear conspicuously less durable

In order not to reduce the life, the load on the tooth surface must be reduced, thereby reducing the torque density (M / a 3 ), which became the popular high torque density (M / a 3 ) The technical contradiction of the power distribution shaft (wheel) system and another significant technical shortcoming

[0055] Thirdly, it is known that the pitch circle diameter of the gears on the shorter outrigger shaft is severely limited by the center distance a and is smaller, and due to the space occupied by the longer outrigger shaft, it is reasonable to arrange symmetrically or roughly symmetrically Described " many to one " can only reach " four to one " at most, so screw rod 1 has limited described prior art high torque density (M / a 3 ) The power distribution shaft (wheel) system continues to increase the torque density (M / a 3 )

[0056] Fourth, so far, the continuous improvement of the torque bearing capacity of the two outstretched shafts (as the shaft itself) has been achieved by continuously replacing them with special steels with higher and higher heat treatment strengths (—— two screw rods similar situation), which leads to a substantial increase in the cost of steel and / or tooling for the two outrigger shafts and is yet another reason why high torque tailside transmissions become expensive

[0091] In summary, the traditional parallel counter-rotating intermeshing twin-screw extruders for extruding plastic materials such as plastics, as well as the anti-traditional parallel counter-rotating intermeshing twin-screw extruders suggested by German patent applications DE2040065-A, DE102006060739-A1 and DE102008029130-A1 Due to the inherent technical defects of the parallel counter-rotating intermeshing twin-screw extruder and its drive components, it is difficult to economically and durably achieve a large torque density (M / a 3 ), that is, 10Nm / cm 3 above, and continue to increase the torque density (M / a 3 ) For the complete machine that adopts the driving assembly of the prior art power distribution shaft (wheel) system and the integral screw, the complete machine faces three structural bottlenecks or a fatigue strength bottleneck—the structural bottleneck is the power distribution shaft (wheel) The bottleneck of the gear transmission capacity of the system, the minimum outer diameter d of the backward extension section of the two screws and the forward extension section of the two extension shafts R Minimum outside diameter d on bottleneck, longer outrigger shaft LA Bottleneck, the fatigue strength bottleneck is the strength obstacle formed by the concentration of tensile stress at the dangerous section, which leads to a significant decrease in the fatigue limit; while continuing to increase the torque density (M / a 3 ) For the drive assembly of the prior art power distribution shaft (wheel) system and the complete machine of the modular screw, at least its drive assembly faces three structural bottlenecks or a fatigue strength bottleneck—that is, the power distribution shaft (wheel) ) is the bottleneck of the gear transmission capacity of the system, and the minimum outer diameter d of the forward extension section of the two extension shafts R Minimum outside diameter d on bottleneck, longer outrigger shaft LA Bottleneck, the fatigue strength bottleneck is the strength barrier formed by the concentration of tensile stress at the dangerous section, which leads to a significant decrease in the fatigue limit

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