Conditioning roller for a conditioning unit of a forage harvester

Abstract

Conditioning roller (28) for a conditioning device (34) of a forage harvester (10), comprising: a roller shell (38) rotatable about a longitudinal axis, which consists of hardened metal or metal provided with a hard coating, and teeth (40) distributed circumferentially around the roller shell (38), which are arranged axially along the entire length of the roller shell (38), wherein the cylindrical outer circle of the roller shell (38), apart from axial end regions (52) on both sides, is designed to taper conically or convexly towards the outside at the two end regions (52).

Description

[0001] The invention relates to a conditioning roller for a conditioning device of a forage harvester, with a roller shell rotatable about a longitudinal axis made of a solid material and teeth distributed circumferentially around the roller shell, which are arranged in an axial direction over the entire length of the roller shell. Technological background

[0002] Forage harvesters are used to harvest whole plants or parts thereof. These are picked up from a field by a harvesting header, compressed by pre-compression rollers, and fed into a chopping drum. The chopping blades of this drum, working in conjunction with a counter blade, cut the plants. The chopped plants or parts are then optionally fed into a conditioning unit and, via a post-accelerator, conveyed into a discharge chute, which transfers them to a transport vehicle. The harvested plants are typically used as animal feed or for biogas production.

[0003] The conditioning unit is used during maize harvesting to break up the kernels contained in the chopped material and improve the digestibility of the feed. The conditioning unit comprises two or more counter-rotating, cooperating rollers, which are pre-tensioned against each other by a pre-tensioning force and between which the chopped material is passed.

[0004] The rollers of the conditioning device are usually provided with teeth or edges extending in the axial direction, so that a non-circular, profiled cross-section of the rollers is obtained, which enables the cooperating rollers to strike the grains (see, for example, DE 83 02 421 U1 with teeth extending over the entire width of the rollers).To improve the comminution effect, it has been proposed to form the teeth from material remaining between two grooves of the roller, with the grooves running in opposite directions helically around the roller and having different flank pitches (EP 1 516 523 A1), or to arrange the axially extending teeth with chamfered side flanks in helically distributed rows around the roller (with axially successive tooth tips) (US 8 480 019 B1), or to have the U-shaped, helical grooves run in opposite directions over the two halves of the roller (EP 3 295 786 A1), or to arrange the axially adjacent teeth also in a helical shape (with a relatively large pitch) (EP 3 417 693 A1), or to arrange the grooves (forming chamfered tooth flanks) in the axial and circumferential directions (DE 10 2011 084). 443 B3).

[0005] While the rollers in the documents cited in the previous paragraph have a circular cylindrical shell, DE 43 04 763 A1 shows a roller shell equipped with teeth for a conditioning roller, which is smooth at the end, i.e. without any teeth.

[0006] German patent DE 1 212 331 A1 discloses cooperating crushing rollers for balers used to process mowed grass. These rollers are made of a rubber-like material and feature spiral grooves. The crushing roller is axially constructed from several sections and is designed as a double cone or with convex end sections. In their resting position, the rollers are in light contact with each other, but during operation they are under considerable pressure, causing the gaps between the rollers to close on both sides of the roller center. The roller taper is designed to generate a substantially uniform pressure over the entire length of the rollers when the shafts bend outwards under the load by a mechanism that presses the upper roller against the lower one.Here, the inherently elastic rollers are therefore convex or conical in shape, but are deformed by the contact pressure in such a way that a closed gap results between them. Task

[0007] As described above, the toothed conditioning rollers are equipped with a circular cylindrical outer ring when new. This ensures a consistently large gap between the rollers across their width, which promotes uniform processing of the crop. However, in operation, more crop typically flows in the center of the rollers than at their edges. Over time, this leads to increased wear in the center, resulting in a smaller diameter. Consequently, after a certain period of inactivity, it becomes impossible to position the rollers close enough together to allow for effective crop processing in the center.The roller shown in DE 43 04 763 A1 does not allow processing of the harvested crop at the edge of the roller, and the crushing rollers according to DE 1 212 331 A1 are, since they are made of inherently flexible material, not suitable for processing harvested crop containing grain in forage harvesters.

[0008] The object underlying the invention is seen as being to provide a conditioning roller for a conditioning unit of a forage harvester which does not have the aforementioned disadvantages or at least has them to a lesser extent. invention

[0009] The present invention is defined by the patent claims.

[0010] A conditioning roller for a conditioning unit of a forage harvester comprises a roller shell made of a rigid material, rotatable about a longitudinal axis, and teeth distributed circumferentially around the roller shell, arranged axially over the entire length of the roller shell. The outer circumference of the conditioning roller (when new) tapers outwards at both axial ends.

[0011] In other words, the conditioning roller, made of a rigid and strong material (especially hardened or coated metal), is equipped with teeth distributed around its circumference along its entire axial length (either continuously or with grooves in between) and is tapered at both ends, e.g., conically or convexly. When new, the end sections of the conditioning roller therefore do not interact, or interact to a lesser extent, than the central section with a second, identical conditioning roller. Because the smaller quantities of crop passing through the end sections compared to the center, this does not significantly impair the conditioning effect.As the teeth of the conditioning roller gradually wear down during harvesting, the roller's circumference becomes increasingly cylindrical, and the entire toothed length of the roller interacts with the crop. This increases the usable service life of the conditioning roller.

[0012] Preferably, the height of the teeth is constant over the entire length of the roller shell. The height of the grooves between circumferentially adjacent teeth is therefore equal in the outwardly tapered end regions to the height of the grooves between circumferentially adjacent teeth in the remaining regions of the conditioning roller. However, it would also be conceivable to choose a greater tooth height in the regions of the roller shell outside the tapered end regions than in the end regions.

[0013] As already mentioned, the teeth can each extend in one piece over the entire length of the roller shell, or only over a part of the length of the roller shell, in which case the axially adjacent teeth are separated by grooves extending circumferentially or helically around the roller shell. The individual teeth (each a single piece or separated by grooves extending circumferentially or helically around the circumference) typically have axially extending longitudinal axes, and longitudinally adjacent teeth can be connected by imaginary connecting lines that extend axially along the roller shell (see, for example, DE 83 02 421 U, DE 10 2011 084 443 B3, EP 3 295 786 A1 or US 8 480 019 B1) or helically (see EP 3 417 693 A1) around the roller shell in a manner known per se, for which reference is made to the cited prior art, the disclosure of which is incorporated into the present documents by reference.

[0014] The groove between axially adjacent teeth can have radially extending walls. These U-shaped grooves, unlike V-shaped grooves, ensure that the tooth shape and geometry in the axial direction are maintained even as the teeth gradually wear down.

[0015] The teeth can be sawtooth-shaped when viewed circumferentially, with the leading flank in the direction of rotation being steeper than the trailing flank in particular. Example of implementation

[0016] An embodiment of the invention is explained with reference to the illustrations. They show: Fig. 1 a schematic side view of a forage harvester, Fig. 2 a perspective view of a conditioning roller, Fig. 3 an enlarged section from Fig. 2, Fig. 4 a cross-section through the conditioning roller along line 4-4 of the Fig. 2, and Fig. 5 a section through an end area of ​​the conditioning roller.

[0017] In the Fig. Figure 1 shows a schematic side view of a self-propelled forage harvester 10. The forage harvester 10 is built on a supporting chassis 12, which is carried by front driven wheels 14 and steerable rear wheels 16. The forage harvester 10 is operated from a driver's cab 18, from which a harvesting head 20, detachably attached to a feed housing 36, is visible. This head 20 is a mowing head for harvesting maize. The harvested crop, cut by the harvesting head 20, e.g., B. maize or the like, is fed at the front of the forage harvester 10 via a feed conveyor with pre-compression rollers 30,32 arranged in the feed housing 36 to a chopping drum 22, which, in conjunction with a counter blade 46, chops it into small pieces and feeds it to a conditioning device 34 with two cooperating conditioning rollers 28, from which it reaches a conveying device 24.The material leaves the forage harvester 10 and is conveyed to a transport vehicle traveling alongside via a discharge spout 26, which is rotatable about an approximately vertical axis and adjustable in inclination. The knives of the chopping drum 22 can be sharpened by a grinding device 42. In the following, directional terms such as lateral, below, and above refer to the forward direction of movement V of the forage harvester 10, which is located in the... Fig. 1 runs to the left.

[0018] It will now be referred to as Fig. Reference is made to Figure 2, which shows one of the conditioning rollers 28. The other conditioning roller 28 is identical, but rotated by 180° so that the leading surfaces 56 of the teeth 40 are the same. The conditioning roller 28 comprises an (approximately, see the following paragraph) cylindrical roller shell 38, which is connected to end shaft stubs 50. These stubs, in turn, are rotatably and driveably supported on bearings in a housing (not shown, but see, for example, EP 2 098 110 A2) of the conditioning device 38.

[0019] The roller shell 38 is equipped with teeth 40, which are separated from each other by axial grooves 48 and grooves 44 extending helically in the circumferential direction around the roller shell 38. The axial end regions 52 are convexly shaped, as shown in the Fig. 5 shown.

[0020] How to use the Fig. As can be seen in Figure 3, the grooves 44, which extend helically in the circumferential direction around the roller shell 38, are provided with radially extending side walls, i.e., they are U-shaped.

[0021] The Fig. Figure 4 shows a section through the conditioning roller 28 along lines 4-4 of the Fig. 2, Fig. i.e. in the radial direction. It can be seen that the axial grooves 48 are designed such that the leading flanks 56 of the sawtooth-shaped teeth 40 in the direction of rotation 54 are steeper than the trailing flanks 58.

[0022] Based on the Fig. Figure 5 shows that the end regions 52 taper outwards, i.e., they are formed with a radius (convex). The depths of the axial grooves 48 and the circumferentially extending grooves 44 (and thus the heights of the teeth 40) are identical in the end regions 52 to the respective depths of the grooves 48 and 44 in the areas of the conditioning roller 28 located between the end regions 52. It is also evident that the roller shell 32 is pushed onto a tube 60, which is supported on the shaft stubs 50 by means of support discs 62. In the embodiment shown, the end region 52 extends from the outer edge of the roller shell 38 to (approximately) the inner wall of the support disc 62. However, the two end regions 52 at both ends of the conditioning roller 28 could also be made wider or narrower than shown in the figures.However, they extend at least over a significant portion of the width of the conditioning roller 28, i.e., a few percent (e.g., at least 5 or 10% on each side), and are not merely end chamfers, as are found, for example, in the . Fig. 2 of the DE 297 19 518 U1 will be shown.

[0023] The Fig. 2 to Fig. Figure 5 shows the conditioning roller 28 in its new condition. After a certain service life, the teeth 40 in the areas between the end sections 52 will wear down, so that the conditioning roller 28 then acquires a perfectly circular cylindrical outline, which subsequently becomes progressively smaller in the center than in the end sections 52. Due to the end sections 52 tapering outwards, but having the same tooth height as the areas in between, a longer service life is achieved compared to previous conditioning rollers 28 which had perfectly circular cylindrical outlines when new. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 8302421 U1

[0004] EP 1516523 A1

[0004] US 8480019 B1 [0004, 0013] EP 3295786 A1 [0004, 0013] EP 3417693 A1 [0004, 0013] DE 102011084443 B3 [0004, 0013] DE 4304763 A1 [0005, 0007] DE 1212331 A1 [0006, 0007] DE 8302421 U

[0013] EP 2098110 A2

[0018] DE 29719518 U1

[0022]

Claims

[1] Conditioning roller (28) for a conditioning unit (34) of a forage harvester (10), comprising: a roller shell (38) rotatable about a longitudinal axis made of a solid material, and teeth (40) distributed circumferentially around the roller shell (38), which are arranged axially along the entire length of the roller shell (38), characterized by , that the circumscribed circle of the conditioning roller (28) is designed to taper outwards at both axial end regions (52). [2] Conditioning roller (28) according to claim 1, wherein the height of the teeth (40) is constant over the entire length of the roller shell (38). [3] Conditioning roller (28) according to claim 1 or 2, wherein the teeth (40) extend in one piece over the entire length of the roller shell (38). [4] Conditioning roller (28) according to one of claims 1 or 2, wherein the teeth (40) each extend over a part of the length of the roller shell (38) and axially adjacent teeth (40) are separated by circumferentially extending or helical grooves (44). [5] Conditioning roller (28) according to claim 3 or 4, wherein imaginary connecting lines between longitudinally adjacent teeth (40) extend axially or helically around the roller shell (38). [6] Conditioning roller (28) according to claim 4 or 5, wherein the groove (44) arranged between axially adjacent teeth (40) has radially extending walls. [7] Conditioning roller (28) according to one of the preceding claims, wherein the teeth (40) are sawtooth-shaped when viewed in the circumferential direction. [8] Conditioning roller (28) according to one of the preceding claims, wherein the end regions (52) are conical or convex. [9] Forage harvester (10) with a conditioning roller (28) according to one of the preceding claims.

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