DE29817981U1 - Gear unit for twin screw extruders - Google Patents

Description

PATENT ATTORNEYS ··***#* ·*+'··' .#* *,

DIPL.-ING. R. LEMCKE DR.-ING. H. J. BROMMER DIPL.-ING. F. PETERSEN DIPL.-ING. D. BLUMENROHR

BlSM ARC KSTRASSE 16 76133 KARLSRUHE TELEPHONE (07 21) 91 28 00

FAX (07 21) 2 11 05

30 September 1998 17 523 (Bl/mr)

P.I.V. Drive Werner Reimers GmbH & Co. KG Industriestraße 3 61352 Bad Homburg

Gearbox for twin screw extruder PATENT ATTORNEYS

DIPL.-ING. R. LEMCKE DR.-ING. H. J. BROMMER DIPL.-ING. F. PETERSEN

DIPL.-ING. D. BLUMENROHR

B IS MARC KSTRASSE 16 76133 KARLSRUHE

TELEPHONE (07 21) 91 28 00 FAX (07 21) 2 11 05

30 September 1998 17 523(BI/mr)

Description

The invention relates to a gear for twin-screw extruders with a first output shaft driven by a drive shaft, in particular via a reduction gear, and a second output shaft driven by the first output shaft via a side shaft, wherein the shafts are arranged axially parallel in a common gear housing.

With regard to such gear housings, various designs are known in the state of the art, with a preferred design being that the gear housing is made up of two housing parts which are secured to one another via a horizontal joint. The joint runs exactly through the axes of the two output shafts and - since the axes of the side shaft also lie in the plane formed by the output shafts - also through the axis of the side shaft, so that when the housing is open, the shafts can be assembled and disassembled and are then freely accessible.

The side shaft, which is in engagement with both output shafts, is located next to the second output shaft on the side facing away from the first output shaft due to the small center distances of the output shafts that are usually used. This results in the problem shown in Figures 3 and 4 that when the center distance between the two output shafts changes, their distance from the side shaft also inevitably changes, which makes a new gearing assembly kit adapted to this changed distance necessary. Even the smallest changes in the center distance therefore always result in the same amount of effort, namely replacing the entire gearing assembly kit.

Based on this, the present invention is based on the object of providing a gear for twin-screw extruders of the type mentioned above, which is characterized by the possibility of varying the center distance of the two output shafts when using the same gearing installation kit.

This object is achieved according to the invention in that the axis of the side shafts is arranged offset from and outside the plane running through the axes of the output shafts. In other words, the side shaft should be moved up or down from the common axis plane relative to the two output shafts, in order to be able to adapt to the respective axis distances of the output shafts.

The fact that the gear train formed by the two output shafts and the side shaft together with the gearing assembly kit is designed in the shape of a triangle, at the corners of which the axes of the gear shafts are located, results in the advantage that the distance between the two output shafts lying horizontally next to each other can be continuously changed, while the distance between the side shaft and the two output shafts remains the same and consequently the same gearing assembly kit can be used.

Accordingly, a main feature of the present invention is that the housing is divided into two housing halves along a joint, and that the joint runs through the bearing seat of the side shaft but not through its axis. As far as the orientation of the joint is concerned, this can run horizontally and expediently through the axes of the two output shafts, as is already known in the prior art with the only exception that the joint also runs through the axis of the side shaft; however, it is particularly advantageous if the joint is oriented vertically and runs between the axes of the two output shafts. The vertical division of the housing results in

The advantage is that the gearbox can be easily assembled or disassembled by opening the housing. For disassembly, this means that when the housing is opened, one of the two output shafts is disengaged from the side shaft and all other shafts - although still securely held in their bearing seats - are freely accessible.

With this form of housing division, the parting plane no longer runs through the shaft axes and thus cannot divide the bearing seats in half. For assembly, this means that the bearing seats, regardless of their respective position in the housing, can only be produced after the housing halves have been manufactured by drilling them into the housing. The individual shafts are then inserted by plug-in assembly or by inserting the shafts and then pressing in the bearings, so again without having to take the center distance of the output or side shaft into account when determining the shape of the housing parts or the position of the parting plane.

This type of bearing seat production would theoretically be possible with horizontal joints, but the use of this method of gearbox assembly usually fails due to the joining and assembly problems that arise with horizontal housing divisions, for example because when the output shafts are mounted, the side shaft with the axis located outside the joint is no longer freely accessible. With horizontal housing divisions, it is more important that all shaft axes are located exactly in the corresponding joint planes, as this is the only way to access the cast-in bearing seats and enable the bearings or shafts to be inserted. However, the center distance can then no longer be changed without also having to adapt and replace the gearing installation kit.

The special position of the vertical joint in particular in relation to the bearing seat or the axis of the side shaft results in the advantage that no bearing forces of the output shafts and also no bearing forces of the

Laterally, the bearings act on the parting plane, since all the associated bearing points are held in the housing webs in a form-fitting manner. In addition, this form-fitting arrangement makes the gearbox much easier to handle, as it can be rotated or swiveled without any auxiliary device even when the housing is open, without bearings or shafts falling out. This means that you only have to unscrew the output lantern and can then open the parting line to access the gearbox.

Finally, it is recommended that the separation plane is arranged parallel to the individual output shafts and thus runs perpendicular to the plane formed by the two output shafts. In addition, with regard to the handling of the gearbox, it can be advantageous if the two housing halves are connected to one another in a pivoting or hinged manner, with the pivot axis being expediently arranged in the area of the lower horizontal edge of the housing halves lying in the separation plane.

Gearbox housings with a vertical separation plane are already known in the state of the art; however, this extends perpendicular to the axes of the output or side shaft, with up to four housing parts arranged one behind the other. This known design also has the major disadvantage that in order to open the housing, the shafts or their bearings must first be removed from the bearing seats, which makes access to the gearbox very cumbersome and very difficult. The initial assembly of the gearbox is correspondingly complicated.

The gearbox according to the invention avoids all of these disadvantages of the state of the art through the advantageous arrangement of the parting line. Because the bearing seats are only subsequently inserted into the housing in precise adaptation to the respective application, the center distance of the output shafts can be continuously changed over a large range without the need for a new gearing installation kit or new housing components.

would be required. The main advantage of this design is that any center distance desired by the customer can be achieved over a larger area and - despite the different center distances - only the same components are required. This means that no new separate gearing installation kits or housing parts need to be provided for different center distances, but only the complete housing needs to be re-drilled.

This is because neither the side shaft nor the output shafts are fixed in their position exactly opposite the parting line and thus they can be arranged almost arbitrarily in the housing - while maintaining the triangular gear train - to which the position of the bearing seats is then adjusted and these are subsequently drilled into the housing.

All of this leads to a significant reduction in the variety of parts and a corresponding increase in the batch sizes for the individual parts, and thus to considerable cost savings overall.

Furthermore, the present invention can cover the range of center distances required by the market for a specific torque range in a stepless manner by overlapping the center distances of different gear sizes. In addition, if a gearbox is required for a large machine with only a low torque requirement, a smaller gearbox size can be used whose maximum output torque corresponds to the required torque and has an increased center distance adapted to the large machine, which leads to a corresponding reduction in costs.

Further features and advantages of the present invention will become apparent from the following description of an embodiment with reference to the drawings, in which:

φφ

Figure 1 shows a transmission housing of a transmission according to the invention in

schematic front view;
Figure 2 the gearbox housing or gearbox from Figure 1 with modified

Output shaft center distance and
Figures 3 and 4 show a gearbox housing according to the prior art with two different output shaft center distances.

Figure 1 shows the schematic front view of a gear housing 3 for a twin-screw extruder gear consisting of two housing halves 1, 2. The gear housing 3 is divided into the two housing halves 1, 2 along a vertical parting line 4 and each of the two housing halves carries an output shaft 5, 6 which leads to a twin-screw extruder (not shown).

In Figure 1, the two output shafts have a mutual center distance X. Figure 1 also shows a side shaft 7 that engages with both output shafts 5, 6, which is driven by the first output shaft and transmits the rotary motion to the second output shaft.

If the center distance of the two output shafts 5 is to be changed with the same gearbox housing 3 or housing halves 1, 2 and with the same gear train, the configuration shown in Figure 2 results: Although the respective positions of the two output shafts and the side shaft have changed compared to the configuration in Figure 1, the distance between the side shaft and the two output shafts has remained the same, so that the same gearing installation kit (not shown) can be used, which ensures the coupling and movement transmission between the gearbox shafts.

This means that when using the same housing parts, the same gear shafts and the same gearing installation kit, gearboxes with different center distances of the output shafts can be made available, which can then be assembled in a simple manner.

that the individual bearing seats can only be subsequently inserted into the housing with precise adaptation to the respective application.

As the bearing seat of the side shaft is crossed by the parting line 4 outside the side shaft axis, there is also the advantage that when the housing is opened, the side shaft is held in a form-fitting manner in the associated housing half 1 and secured against falling out. The same applies to the output shafts 5 and 6 and the associated bearing seats, although these are arranged at a distance from the parting line 4 anyway.

Finally, Figures 3 and 4 show a gear housing 3' with a gear for a twin-screw extruder according to the prior art, in which a side shaft 7' and two output shafts 5', 6' are arranged with their axes on the same plane and a horizontal parting line 4' dividing the housing 3' into two housing halves V ₁ 2' runs through the axes of the side shaft 7' and output shafts 5' and 6'. This results in the disadvantage deducible from Figures 3 and 4 that when the axis distance X' between the output shafts 5' and 6' is changed to the axis distance X' + Y', the distance to the side shaft 7' is also inevitably changed by the latter being moved outwards along the parting line. This makes a new gear installation kit necessary even if the change in the axis distance is only very small.

In summary, the present invention offers the advantage that, when using the same components, gears with variable center distances can still be made available, which reduces production, storage and assembly costs accordingly. If the joint for dividing the housing is also advantageously arranged vertically between the two output shafts, this also results in the advantage of greatly simplified assembly and disassembly.

Claims (5)

PATENT ATTORNEYS DIPL.-ING. R. LEMCKE DR.-ING. H. J. BROMMER DIPL.-ING. F. PETERSEN DIPL.-ING. D. BLUMENROHR BlSMARCKSTRASSE 16 76133 KARLSRUHE TELEPHONE (07 21) 91 28 00 FAX (07 21) 2 11 OS 30 September 1998 17 523 (Bl/mr) Protection claims 1. Gearbox for twin-screw extruders with a first output shaft driven by a drive shaft, in particular via a reduction gear, and a second output shaft driven by the first output shaft via a side shaft, the shafts being arranged axially parallel and in a common gear housing, characterized in that that the axis of the side shaft is arranged at a distance from the plane passing through the axes of the output shafts. 2. Transmission according to claim 1,
characterized, that the housing (3) is divided into two housing halves (1, 2) along a vertical parting line (4), and that the parting plane runs between the axes of the two output shafts (5, 6). 3. Transmission according to claim 1,
characterized, that the parting line (4) runs through the bearing seat of the side shaft (7). 4. Transmission according to at least one of the preceding claims, characterized in that the parting line (4) is arranged parallel to each of the two output shafts (5, 6). t ·*· 5. Transmission according to claim 4, characterized in that the parting line (4) is arranged perpendicular to the plane formed by the two output shafts (5, 6).