Length-adjustable screw conveyor assembly for a combine harvester

Abstract

Length-adjustable screw conveyor assembly (56) for a combine harvester (10), comprising: a first tube (60) in which a first screw conveyor (66) which can be set in rotation by a drive is arranged, comprising a central, first support tube (68) and a first conveying helix (70) which runs around the first support tube (68) and is attached to it, and a second tube (62) in which a second screw conveyor (72) is rotatably mounted, comprising a central, second support tube (74) and a second conveying helix (76) surrounding the second support tube (74) and attached to it, wherein the first pipe (60) can be pressurized with conveyed material at its inner end, the second pipe (62) has a discharge opening (80) at its outer end and is axially displaceable relative to the first pipe (60), and wherein one of the support tubes (68, 74) is located at an end region within the end region of the other support tube (74, 68) and one or more turns of the second conveying helix (76) are located, at least in the inserted state of the second tube (62), between turns of the first conveying helix (70) or in conjunction with it, characterized in that the support tube (68, 74), into which the end region of the other support tube (74, 68) penetrates, has a helical slot (84) in its end region, through which the conveying helix (76, 70) connected to the other support tube (74, 68) extends, which is connected to its support tube (74, 68) in its region penetrating the slot (84).

Description

[0001] The invention relates to a length-adjustable screw conveyor assembly for a combine harvester, comprising: a first tube in which a first screw conveyor, which can be set in rotation by a drive, is arranged, comprising a central, first support tube and a first conveying helix running around the first support tube and attached to it, and a second pipe in which a second screw conveyor is rotatably mounted, comprising a central, second support pipe and a second conveying helix surrounding the second support pipe and attached to it, wherein the first pipe can be pressurized with conveyed material at its inner end, the second pipe includes a discharge opening at its outer end and is axially displaceable relative to the first pipe, and wherein one of the support tubes is located at an end region within the end region of the other support tube and one or more turns of the second conveying helix are located, at least in the inserted state of the second tube, between turns of the first conveying helix or in conjunction with it. State of the art

[0002] Agricultural combine harvesters are large machines that harvest, thresh, separate, and clean grain crops. The resulting clean grain is stored in a grain tank mounted on the combine. When the grain tank is sufficiently full, an unloading process takes place, during which the grain is removed from the tank by a screw conveyor assembly and discharged onto a transport container moving alongside the combine, either pulled or carried by a vehicle, or self-propelled. The screw conveyor assembly consists of a tube containing a rotatable screw conveyor. The tube can pivot around its vertical axis between an unloading position, in which it extends laterally outward from the combine, and a transport position, in which it extends backward.

[0003] As the throughput of combine harvesters continues to increase, ever wider headers are being used. The grain hopper and, if applicable, its towing vehicle travel alongside the header, meaning that the length of the auger conveyor assembly must correspond to approximately half the width of the header. The length of the auger conveyor assembly can thus reach approximately 10 meters. To prevent it from extending further than permitted beyond the rear of the combine harvester in the transport position, longer auger conveyor assemblies are, according to the prior art, foldable (EP 1 330 948 A1) or length-adjustable. Auger conveyors are also used in combine harvesters for filling the grain tank and for return conveying (see DE 101 53 790 A1).

[0004] The JP 2000 - 209 938 A describes a length-adjustable unloading screw conveyor for a combine harvester, in which inner pipes equipped with coils are arranged to be displaceable relative to each other in the axial direction.

[0005] Such a length-adjustable screw conveyor assembly is described in JP H09-56248A, which is considered to define the generic form of the invention. It comprises a first tube, supported on the combine harvester, in which a first screw conveyor is rotatably and driveably mounted. The first screw conveyor includes a central support tube and a first conveying helix surrounding it. The first tube is pivotally mounted to the combine harvester about its vertical axis in a manner known per se. A second tube rests against the outer end of the first tube and is axially displaceable relative to the first tube to allow the length of the screw conveyor assembly to be changed between a retracted transport position and an extended unloading position. The unloading opening is located at the outer end of the second tube. A second screw conveyor is arranged inside the second tube and rotatably mounted at its outer end.The second screw conveyor also comprises a central, second support tube and a second spiral conveyor around it, the inner coils of which rest against the outer coils of the first spiral conveyor of the first screw conveyor. The inner end of the second support tube extends (more or less far, depending on the extension position of the screw conveyor assembly) into the first support tube. When the length of the screw conveyor assembly is adjusted, the spiral of the second screw conveyor is thus unscrewed from or screwed onto the spirals of the first screw conveyor to a greater or lesser extent.

[0006] One disadvantage of the described screw conveyor assembly is that the second spiral can only be attached to the second support tube at its outer end. This is because the second spiral is otherwise positioned at a distance from the second support tube, allowing it to contact the outer surface of the first support tube and the first spiral. Particularly when extended, significant portions of the second spiral are therefore unsupported (not attached to the second support tube), which limits the conveying capacity of the screw conveyor assembly. At excessively high throughputs, the second spiral would deform. The gap between the second spiral and the second support tube also reduces the conveying performance. Task

[0007] The object underlying the invention is seen as being to provide a screw conveyor assembly that does not have the aforementioned disadvantages or has them to a lesser extent. invention

[0008] The present invention is defined by the patent claims.

[0009] A length-adjustable screw conveyor assembly for a combine harvester comprises a first tube in which a first screw conveyor, rotatable by a drive, is arranged. This first screw conveyor includes a central support tube and a first conveying helix surrounding and attached to the first support tube. The assembly also comprises a second tube in which a second screw conveyor is rotatably mounted. This second screw conveyor includes a central support tube and a second conveying helix surrounding and attached to the second support tube. The first tube can be loaded with material at its inner end. The second tube has a discharge opening at its outer end and is axially displaceable relative to the first tube. One of the support tubes (preferably the first support tube) is located at one end within the end of the other (preferably the second) support tube.One or more turns of the second conveying helix are located, at least when the second pipe is inserted, between turns of the first conveying helix or in contact with it. The support pipe into which the end section of the other support pipe penetrates (preferably the first support pipe) has a helical slot in its end section, through which the conveying helix connected to the other (preferably the second) support pipe extends, and which is connected to its (preferably the second) support pipe in the section penetrating the slot.

[0010] The conveying helix penetrating the slot can be connected to its support tube continuously or intermittently (i.e. at regular or irregular intervals) along its entire length.

[0011] Accordingly, the second conveying helix is ​​screwed more or less far onto or between the first conveying helix, and the first (or second) support tube is pushed more or less far into the first (or second) support tube when the second tube is axially displaced relative to the first tube, e.g., between a retracted transport position and an extended unloading position. Intermediate positions are also possible, e.g., when using narrower harvesting attachments. To increase the stability of the second (or first) conveying helix, it is not only attached to the second (or first) support tube at its outer end, as provided for in the prior art according to JP H09-56248A, but also at other points at a distance from the outer end of the second (or inner end of the first) conveying helix, in particular continuously or intermittently.To facilitate this connection between the second (or first) support tube and the second (or first) conveying helix, the first (or second) support tube is provided with a slot through which the second (or first) conveying helix extends. This slot is directly adjacent to the second (or first) conveying helix, although a certain distance from it could also be provided. As mentioned above, the arrangement can also be reversed, in which the first support tube extends into the second support tube, which has the slot.

[0012] The screw conveyor assembly can be used particularly as an unloading conveyor. It can also serve as a grain tank filling screw conveyor, which is extended during operation and retracted otherwise, or as a return conveyor whose length adjustment allows for the appropriate feeding of a secondary combine or threshing unit on a side slope. Example of implementation

[0013] The drawings illustrate an embodiment of the invention, which is described in more detail below, and the reference numerals are not to be interpreted restrictively. They show: Fig. 1 A schematic side view of a combine harvester with a length-adjustable screw conveyor assembly, Fig. 2 a vertical sectional drawing through the screw conveyor assembly in the retracted position, Fig. 3 a vertical sectional drawing through the screw conveyor assembly in the extended position, Fig. 4 a perspective view of the first screw conveyor, and Fig. 5 a perspective view of the second screw conveyor.

[0014] The Fig. Figure 1 shows a self-propelled combine harvester 10 with a frame 12, which is supported on the ground by driven front wheels 14 and steerable rear wheels 16 and is moved by these. The wheels 14 are set in motion by means of drive mechanisms (not shown) to move the combine harvester 10, for example, across a field to be harvested. In the following, directional terms such as front and rear refer to the direction of travel V of the combine harvester 10 during harvesting.

[0015] A harvesting device 18 in the form of a cutting unit is detachably attached to the front end of the combine harvester 10. This device harvests crops, such as grain or other threshable cereals, from the field during harvesting and feeds them upwards and backwards via an inclined conveyor 20 to a multi-drum threshing unit. This unit comprises a threshing drum 22, a stripping drum 24, an overshot conveying drum 26, a tangential separator 28, and a reversing drum 30, arranged one behind the other in the direction of travel V. A straw walker 32 is located downstream of the reversing drum 30. The threshing drum 22 is surrounded in its lower and rearward area by a concave 34.Below the conveyor drum 26 is a cover 35, either with openings or closed, while above the conveyor drum 26 is a fixed cover and below the tangential separator 28 is a separating basket 36 with adjustable finger elements. A finger rake 38 is arranged below the reversing drum 30.

[0016] The mixture containing grains and impurities, passing through the threshing concave 34, the separating concave, and the straw walkers 32, is conveyed via conveyor floors 40, 42 into a cleaning unit 46. Grain cleaned by the cleaning unit 46 is fed by a grain screw conveyor 48 to an elevator (not shown), which transports it into a compost tank 50. A return screw conveyor 52 returns unthreshed ear fragments to the threshing process via another elevator (not shown). The chaff can be ejected at the rear of the sieving unit by a rotating chaff spreader, or it can be discharged by a straw chopper (not shown) located downstream of the straw walkers 32. The cleaned grain from the grain tank 50 can be unloaded by an unloading system with transverse screws 54 and a screw conveyor assembly 56.

[0017] The aforementioned systems are driven by an internal combustion engine 58 and controlled and operated by an operator from a driver's cab 61. The various devices for threshing, conveying, cleaning, and separating are located within the frame 12. Outside the frame 12 is an outer shell, which is largely hinged. It should be noted that the multi-drum threshing system shown here is only one embodiment. It could also be replaced by a single transversely arranged threshing drum and a downstream separating device with a straw walker or one or more separating rotors.

[0018] The screw conveyor assembly 56, serving as an unloading conveyor, comprises a first, inner tube 60, which is supplied with grain from the grain tank 50 by the transverse screws 54 and a vertical section (not shown) of the screw conveyor assembly 56. The vertical section is supported on the frame 12 and, in a manner known per se, also includes a rotary bearing (see, for example, EP 1 186 222 A1) for pivoting the screw conveyor assembly 56 about its vertical axis. A second, outer tube 62 is axially displaceable (telescoping) relative to the first tube 60 by means of an actuator 64, which can be designed as a hydraulic cylinder, with the second tube 62 being located outside the first tube 60, as shown in the Fig. 2 and Fig. 3 shown, or can be arranged within the first tube 60. In this way, the screw conveyor assembly 56 can be transported into a retracted position (cf. Fig. 1 and Fig. 2) and for unloading operation into an extended position (see Fig. 3) or be moved into an intermediate position. Directional terms such as inside and outside refer below to the conveying direction of the discharge screw assembly 56, which is located in the Fig. 1 runs from left to right.

[0019] Within the first tube 60, a first screw conveyor 66, which can be set in rotation by a drive, is arranged. This conveyor comprises a central, first support tube 68 and a first conveying helix 70, which runs around the first support tube 68 and is attached to it. The first support tube 68, which can be hollow, partially solid, or entirely solid except for the end region, as shown in the Fig. 2 shown, is at its inner end (in Fig. 2 (not visible) rotatably mounted relative to the tube 60 and connected to the internal combustion engine 58 by a drive train in order to rotate it when required.

[0020] Inside the second tube 62, a second screw conveyor 72 is rotatably mounted. This conveyor comprises a central, second support tube 74 and a second conveying helix 76, which encircles the second support tube 74 and is attached to it. The second support tube 74 can also be hollow or made entirely or partially solid. The second screw conveyor 72 is supported at its outer end by a rotary bearing 78 on the second tube 62. A discharge opening 80 is located at the outer end of the second screw conveyor 72, through which the harvested material can be discharged onto a transport vehicle. The inner end region of the second support tube 74 extends into an axial opening 82 provided in the outer end region of the first support tube 68. In the simplest case, this opening can be formed by the interior of the first support tube 68, which is designed as a hollow tube. The second support tube 74 is axially displaceable and rotatably mounted within the opening 82.

[0021] In the withdrawn position after Fig. 2. Some of the inner turns of the second conveying helix 76 are in contact with some of the outer turns of the first conveying helix 70 (or have a relatively small axial distance to them), i.e., the second conveying helix 76 is screwed onto the first conveying helix 70, and this contact is more pronounced the further the second tube 62 is retracted. As the second tube 62 is withdrawn, the actuator 64 unwinds the second conveying helix 76 from the first conveying helix 70. This means that the second screw conveyor 72 rotates about its longitudinal axis due to the movement of the actuator 64, which, along with the bearing 78, also pulls the second screw conveyor 72 outwards. If the pitch of the conveying helixes 70 and 76 is too small for this forced rotation, a separate adjusting drive could be used to rotate the second screw conveyor 72 relative to the first screw conveyor 66. This adjustment drive would replace actuator 64.The rotational position of the second tube 74 and the second screw conveyor 72 is ultimately defined by the position of the actuator 64 and the rotational position of the first screw conveyor 66.

[0022] The conveying helix 70 of the first screw conveyor 66 is continuously or at regular intervals connected to the first support tube 68, in particular by welding. Similarly, the conveying helix 76 of the second screw conveyor 72 is also continuously or at regular intervals connected to the second support tube 74, in particular by welding. To enable this fastening, which significantly improves the stability of the second screw conveyor 72 and increases its conveying capacity, while still allowing the two conveying helixes 70, 76 to be bolted together, a helical slot 84 is arranged in the first support tube 68. In the illustrated embodiment, this slot 84 is directly adjacent to the conveying helix 70, but could also be located at a certain distance from it. The second conveying helix 76 extends through this slot 84. The slot 84 can be located on the inside of the first conveying helix 70, as shown in Fig. 2 and Fig.4 shown, or on their outside, or at any point in between.

Claims

[1] Length-adjustable screw conveyor assembly (56) for a combine harvester (10), comprising: a first tube (60) in which a first screw conveyor (66) is arranged, which can be set in rotation by a drive and which comprises a central, first support tube (68) and a first conveyor spiral (70) fastened thereto and rotating around the first support tube (68), and a second tube (62) in which a second screw conveyor (72) is rotatably mounted, which comprises a central, second support tube (74) and a second conveyor spiral (76) attached to and rotating around the second support tube (74), wherein the first tube (60) can be loaded with conveyed material at its inner end, the second tube (62) comprises a discharge opening (80) at its outer end and is axially displaceable relative to the first tube (60), and wherein one of the support tubes (68, 74) is located at an end region within the end region of the other support tube (74, 68) and one or more turns of the second conveyor spiral (76) are located between turns of the first conveyor spiral (70) or in contact therewith, at least in the inserted state of the second tube (62), characterized by that the support tube (68, 74) into which the end region of the other support tube (74, 68) penetrates has a helical slot (84) in its end region through which the conveyor spiral (76, 70) connected to the other support tube (74, 68) extends, which is connected to its support tube (74, 68) in its region penetrating the slot (84). [2] The screw conveyor assembly (56) of claim 1, wherein the second support tube (74) is located within the first support tube (68) having the slot (84) through which the second conveyor helix (76) extends. [3] Screw conveyor assembly (56) according to claim 1 or 2, wherein the conveyor helix (76, 70) penetrating the slot (84) is connected continuously or intermittently to its support tube (74, 68) over its entire length. [4] Screw conveyor assembly (56) according to one of the preceding claims, which is designed as an unloading conveyor for unloading a grain tank (50) or as a filling screw for filling a grain tank (50) or as a return conveyor. [5] A combine harvester (10) having a screw conveyor assembly (56) according to any one of claims 1 to 4.

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