DRIVE DEVICE FOR DRIVING A PAIR OF AGRICULTURAL ROLLERS AND A FARM MACHINE WITH SUCH A DRIVE DEVICE

Description

[0001] The present invention relates generally to agricultural machines with a cooperating pair of rollers, the rollers of which can be driven in opposite directions by a drive device.

[0002] Agricultural machinery uses pairs of interacting rollers that rotate in opposite directions, for example, to convey crops between the rollers and process them through the action of the rollers. It may be necessary or desirable to synchronize or precisely match the roller speeds, for example, if the rollers have interlocking, relief-like surface structures such as grooves, or if the crop is to be subjected to pressure but not crushed.

[0003] For example, such roller pairs are used in conditioners, which can be located downstream of the mower unit of a combine harvester or upstream of the belt conveyor of a merger (see US 2015 / 0052866 A1). Such roller pairs may also be used in other agricultural machinery, such as grain crushers or crop choppers.

[0004] Depending on the processing task and machine type, it may be necessary or desirable to mount the rollers so that they can move transversely to the roller axis of rotation. This allows the gap between the rollers to be adjusted, for example, to adapt to the crop flow or to increase it in case of impending overload. The drive mechanism must also be at least partially movable transversely to the drive or roller axis of rotation to accommodate these adjustment movements. Depending on the roller mounting, not only uniaxial adjustment movements, where the gap remains constant along the length of the rollers, can occur, but also tilting movements that, for example, increase or decrease the gap more at one end of the rollers than at the opposite end.

[0005] Various drive devices are known for roller conditioners, such as endless toothed belt or chain drives, which can easily compensate for or accommodate the aforementioned movements or offset of the rollers. Alternatively, it is also known to drive the rollers via a spur gear drive, where the spur gear typically serves as a synchronization stage, transferring the rotational speed of one roller to the other by reversing its direction of rotation. In this process, one of the rollers is driven, possibly at the opposite end, so that the spur gear stage transmits the drive motion of one roller to the other.

[0006] For example, US patent 62 20 007 B1 shows a roller conditioner for a mowing machine in which the two conditioner rollers are synchronized via a spur gear stage. The lower roller is driven at one end, while a spur gear stage is mounted at the opposite end to transmit the drive motion of the lower roller to the upper roller (see also EP 3 973 765 A1 and NL 1 023 352 C2). To allow for changes in the distance or gap between the rollers, two meshing spur gears can pivot together with the pivoting linkage on which one of the rollers is pivotally mounted, with a third spur gear also pivotally mounted on the aforementioned linkage.To avoid the synchronization offset that occurs in this process, US 71 88 461 B2 proposes a modified spur gear transmission in which two meshing spur gears of the four-gear spur stage are arranged coaxially to the pivot axes of the pivot links. Another spur gear transmission for driving agricultural conditioner rollers is shown in EP 28 48 111 B1.

[0007] These previously known drive devices with a spur gear transmission are, however, relatively bulky and also massively constructed in order to absorb the bearing forces of the rollers. At the same time, the driven roller is subjected to high torsional stress along its length, while on the other hand, the processing or pressing force of the rollers depends on the transmitted drive force.

[0008] The present invention is based on the objective of creating an improved drive device and an improved agricultural machine of the aforementioned type, which avoid the disadvantages of the prior art and advantageously further develop the latter. In particular, a compact, easily sealed roller drive is to be created that can compensate for angular errors and axial misalignment between the rollers.

[0009] According to the invention, the aforementioned problem is solved by an agricultural machine according to claim 1. Preferred embodiments of the invention are the subject of the dependent claims.

[0010] It is therefore proposed to drive the rollers of the cooperating roller pair from a separate drive shaft via two spur gear drives, each transmitting the drive motion from the drive shaft to the respective roller. According to the invention, the drive device has a first spur gear drive with an odd number of spur gears for driving a first roller of the roller pair and a second spur gear drive with an even number of spur gears for driving a second roller of the roller pair, wherein a common drive shaft, on which both spur gear drives with one input spur gear each are mounted, is provided and arranged offset from the rollers.

[0011] Due to the shared drive shaft, offset from the rollers, neither roller needs to transmit the drive power or torque for the other, so each roller only needs to be loaded with its own drive power. Simultaneously, the drive, along with the spur gear stage, can be combined on one side of the rollers, with the even and odd numbers of spur gears enabling counter-rotation of the rollers at synchronous or precisely matched speeds. The spur gears allow for the transmission of high power without the drive forces negatively impacting the crushing or conditioning force of the roller pair.

[0012] To achieve the most compact design possible, while still allowing counter-rotating drive of the rollers from the common drive shaft, the first spur gear unit can have three spur gears and the second spur gear unit two spur gears. In principle, it would also be possible to use spur gear units with three or four spur gears, or four and five spur gears, but this would lead to an unnecessary increase in size. A design with two or three spur gears, on the other hand, can not only be more compact, but also transmit the drive forces with minimal loss, misalignment, and backlash, since rolling resistances, engagement resistances, and any transmission misalignment due to elasticity or backlash do not accumulate over longer spur gear chains.

[0013] In an advantageous embodiment of the invention, the two spur gear units can be housed in separate gearboxes or at least in separate gearbox chambers sealed against each other, thereby significantly simplifying the sealing process. Advantageously, the two spur gear units can be sealed separately and have separate lubricant reservoirs. The lubricant reservoirs can be sealed not only against the environment but also against each other.

[0014] In particular, the two spur gear units, together with their separate gearbox housings, can be movable relative to each other, especially pivotable about a pivot axis, so that one spur gear unit can pivot relative to the other and be brought into different angular positions. This pivot axis can, in particular, extend coaxially to the common drive axis, so that the spur gear units can pivot relative to each other about the drive axis.

[0015] In an advantageous embodiment of the invention, the two spur gear units can be axially offset from each other in the direction of the drive shaft, so that when viewed in a direction parallel to the drive shaft, one spur gear unit is arranged behind the other. This axially offset arrangement of the spur gear units can be achieved, in particular, by arranging the two input spur gears of the two spur gear units one behind the other on the drive shaft. The two input spur gears can be mounted coaxially one behind the other on the drive shaft and, if necessary, spaced apart from each other to allow separate housing in separate gear chambers.

[0016] In principle, it would also be possible to use a twin spur gear as the input gears for the two spur gearboxes, possibly with a slot between the two rolling sections in which a housing wall could extend. Preferably, however, the two spur gearboxes have separate input spur gears, which are housed in separate gearbox casings and can be mounted separately onto the drive shaft.

[0017] Viewed from a perspective parallel to the drive shaft, the two spur gear units and their gearboxes can form an approximately V-shaped, splayed arrangement extending from the common drive shaft to the two rollers. The angle of this V-shaped arrangement can change to accommodate or follow changes in the distance between the two rollers.

[0018] The aforementioned pivotability of the two spur gear drives allows the driven rollers to be mounted transversely to their longitudinal axes so that the gap between the two rollers can be adjusted. In particular, one of the rollers, especially the upper roller, can be pivotally mounted, for example, on a rocker arm or a pair of rocker arms, allowing it to move away from and towards the other roller. Independently of this, the other roller, especially the lower roller, can be rotatably but fixedly mounted on a frame.

[0019] By allowing the two rollers to be mounted with variable distances or gaps between them, they can adapt to the flow of harvested material being processed, in particular by moving further apart or yielding to each other in order to open up in case of an increasing flow of harvested material or even a blockage.

[0020] In an advantageous embodiment of the invention, the spur gear drive with the smaller number of spur gears is assigned to the pivotably or variable-distance mounted roller. This allows the movable roller to react more easily to changes in the crop flow and to adjust its distance from the other roller. If spur gear drives with two or three spur gears are provided in the aforementioned manner, the two-wheeled spur gear drive of the pivotably mounted roller can be assigned in such a way that, in the event of impending blockages or a sharp increase in drive resistance at the pivotally mounted roller, a self-opening effect is achieved, and the drive forces or torques transmitted via the two spur gears attempt to move the movable roller away from the other roller.

[0021] In a further development of the invention, the spur gear drive with the larger number of spur gears can be assigned to a roller of the roller pair, which is rotatably but fixedly mounted on the frame.

[0022] Advantageously, the aforementioned roller, which is movably or pivotably mounted, is suspended and supported by a separate suspension system, such as a pivoting linkage, independent of the spur gear drives. This prevents any contact or bearing reaction forces resulting from the roller's movable suspension from acting on the spur gear drive that powers the roller. The spur gear drive only transmits the drive forces and does not have to transmit any additional bearing reaction forces that would hold the roller in position. These bearing reaction forces are absorbed by the separate suspension system or the pivoting linkage.

[0023] In order to compensate for tilting movements of the movably suspended roller about a tilting axis perpendicular to the roller's longitudinal axis or axis offset, the spur gear drive for driving the movably suspended roller can be articulated, in particular elastically articulated, to the roller, wherein the articulated connection between the output shaft of the spur gear drive and the roller allows one or more axial tilting movements with respect to one or more tilting axes perpendicular to the roller's longitudinal axis and / or transverse offset of the output shaft to the roller's axis of rotation, but on the other hand can transmit drive forces or torques with respect to the rotary drive movement.

[0024] Advantageously, such an elastically articulated connection can include an elastic, for example rubber-elastic, connecting element, which may be designed, for instance, in the form of a connecting plate. This elastic connecting element undergoes deformation and allows such deformation when the driven roller tilts relative to the output shaft of the spur gear drive, so that the longitudinal axis of the roller is no longer aligned with the output shaft or its longitudinal axis.

[0025] The elastic element mentioned above can connect a connecting element rigidly attached to the roller with a connecting element rigidly connected to the drive shaft of the spur gear unit, or be inserted between these two rigidly attached connecting elements.

[0026] To avoid uneven rotation or imbalance, the output shaft of the spur gear can be connected to the driven roller by a centering device that centers the drive shaft to the roller and avoids imbalances due to deformations of the elastically articulated connection.

[0027] In an advantageous embodiment of the invention, the spur gear assembly can have exactly one input shaft and exactly two output shafts, wherein said input shaft is the common drive shaft for the two spur gear stages and the two output shafts can be rotationally fixed to the two rollers. The output shafts can be arranged at least approximately in alignment with the roller axes of rotation.

[0028] In an advantageous further development of the invention, the spur gears of the spur gear transmissions can be designed as toothed gears and be in comb mesh with each other.

[0029] The invention is explained in more detail below with reference to a preferred embodiment and the accompanying drawings. The drawings show: Fig. 1: A perspective view of a pair of rollers and a drive device for driving the rollers in opposite directions with two spur gear drives of an agricultural machine, which according to an advantageous embodiment of the invention can be designed as a conditioner. Fig. 2: A perspective view of the two spur gear drives of the drive device. Fig. 1, which shows the two spur gear units mounted on a common drive shaft and a suspension link for the upper roller that can pivot around the drive shaft, Fig. 3: a perspective view of the two spur gear units from the drive shaft side, Fig. 4: a top view of the two spur gear units from the preceding figures, showing the opposing directions of rotation of the output shafts of the two spur gear units, Fig. 5: a sectional view of the two spur gear units through the common drive shaft, showing the input spur gears of the spur gear units arranged axially next to each other and mounted on the common drive shaft, and Fig. 6: a partially enlarged sectional view of the connection of the output shaft of the spur gear unit to the movably suspended roller by means of an elastic element.

[0030] How Fig. 1As shown, the counter-rotating roller pair 1 can comprise two rollers 2 and 3 that extend approximately parallel to each other and rotate in opposite directions to convey a flow of harvested material between them. These rollers 2 and 3 can be provided with a surface profile, for example in the form of a helical relief profile, whereby the profile elements can interlock when the rollers 2 and 3 rotate synchronously.

[0031] The roller pair 1 can be used specifically for feed preparation, for example, to break down green fodder by pressure and / or deformation as it passes through the roller pair 1. Regardless of the specific processing purpose, the rollers 2 and 3 mentioned can form crushing rollers. The roller pair 1 of the conditioner can, for example, be located downstream of the mowing units of a mower or upstream of the conveyor belt of a merger. Depending on the design, the roller pair 1 can also be located elsewhere on the agricultural machine.

[0032] As the figures show, the two rollers 2, 3 are driven by a drive device 4 which includes two spur gear transmissions 5, 6 which drive the two rollers 2, 3 from a common drive shaft 7.

[0033] As the Figures 1-3As shown, the aforementioned drive shaft 7 can be arranged offset from the axes of rotation of the two rollers 2, 3, with the drive shaft 7 and the two axes of rotation of the rollers 2, 3 forming, for example, a triangle. The drive shaft 7 can be arranged in a region between the two rollers 2, 3, but outside the contours of the rollers 2, 3, when viewed from a perspective parallel to the drive shaft 7.

[0034] The distance of the drive shaft 7 from one of the rollers 3 can be greater than from the other roller 2, especially because the spur gear drives 5, 6 can have different numbers of spur gears.

[0035] In particular, a first spur gear unit 5 can have an odd number of spur gears and the second spur gear unit 6 an even number of spur gears. For a particularly compact design, the aforementioned first spur gear unit 5 can have three spur gears and the second spur gear unit 6 two spur gears. With two- and three-wheel configurations of the spur gear units 5, 6, not only can the size and weight of the drive device 4 be kept small, but an efficient and crisp transmission of the drive movements without elasticity is also achieved, so that the rollers 2, 3 rotate exactly synchronously or at the exact desired speed ratio.

[0036] The aforementioned spur gears can all have the same pitch circle diameter or the same number of teeth. Alternatively, to achieve a reduction or gear ratio, it is also possible to use pairs of gears with identical pitch circle diameter ratios or tooth number ratios.

[0037] As the Figures 2 and 3 As shown, the spur gear units 5, 6 have their own gearbox housings 8, 9, which can be sealed both against each other and against the environment by a suitable seal. The aforementioned spur gear units 5, 6 can each include their own lubricant reservoir, which can be sealed against the environment and also against the lubricant reservoir of the other spur gear unit by a suitable seal.

[0038] The two spur gear units 5 and 6 can each be mounted with an input spur gear 10 or 11 on the common drive shaft 7, so that the two input spur gears 10, 11 are arranged coaxially to each other and one behind the other in the axial direction of the drive shaft 7, cf. Fig. 5 .

[0039] The two spur gear units 5, 6 are therefore arranged axially offset from each other in the direction of the drive shaft 7 or threaded one behind the other onto the drive shaft 7.

[0040] Preferably, both spur gear drives 5, 6 are arranged on the same side or at the same end face of the roller pair 1.

[0041] Advantageously, the two spur gear units 5, 6, in particular their gear housings 8, 9, are pivotable relative to each other, about a pivot axis parallel to the drive shaft 7, so that the spur gear units 5, 6 can follow or compensate for pivoting movements of the rollers 2, 3.

[0042] For example, one of the rollers, such as the lower roller 2, can be rotatably but stationary mounted on an aggregate frame 12, while the other roller 3, such as the upper roller, can be movably suspended to allow its distance to the other roller to be changed or adjusted. In particular, the movably suspended roller 3 can be pivotally mounted about a pivot axis, which can be arranged coaxially with the drive shaft 7, by means of a pivot linkage 13.

[0043] Instead of a pivot link arrangement 13, another suspension bearing may also be considered, for example a cam guide, by means of which the movable roller 3 can be moved, for example, on a circular arc path around the drive shaft 7 in order to vary the distance to the fixed roller 2.

[0044] Advantageously, the pivotable or movable roller 3 is in any case suspended by a bearing arrangement separate from the drive device 4 in order not to transmit any bearing forces to the spur gear drives 5, 6.

[0045] Preferably, the movably suspended roller 3 is driven by the second spur gear unit 6 with the smaller number of spur gears, in particular the spur gear unit 6 with only two spur gears. This allows not only a particularly responsive reaction of the roller 3 to volume changes in the crop flow, but also a self-opening effect for the roller 3 in the event of an impending blockage.

[0046] How Fig. 2 To illustrate, the spur gear 6 for driving the movably suspended roller 3 can be arranged further away from the end face of the roller pair 1 than the spur gear 5, which drives the rotatably but fixedly mounted roller 2, cf. Fig. 2 .

[0047] If one considers the drive device 4 with a viewing direction parallel to the longitudinal axis of the common drive shaft 7, cf. Fig. 4The two spur gear units 5, 6, in particular their gear housings 8, 9, can form a V-shaped arrangement extending from the common drive shaft 7 to the two rollers 2, 3. The angle of the V, or spread angle, between the two spur gear units 5, 6 can change to accommodate or allow the spacing movements of the two rollers 2, 3.

[0048] To compensate for angular errors and axial misalignment between the output shaft of the spur gear drive and the associated roller, a pivotable, in particular elastically pivotable, connection 14 can be provided between the gear output shaft and the roller. This connection transmits the rotary drive motion to the roller while simultaneously allowing for angular or axial misalignment. Advantageously, such an elastically pivotable connection 14 can comprise an elastic, in particular rubber-elastic, connecting element 15, which can, for example, be ring-shaped or plate-shaped.

[0049] The elastic connecting element 15 mentioned above can be arranged, in particular, between a connecting element 16 rigidly connected to the drive shaft and a connecting element 17 rigidly connected to the roller, wherein the connecting elements 16 and 17 mentioned above can, for example, be designed in the form of a connecting flange extending approximately radially or transversely to the direction of rotation. The elastic connecting element 15 mentioned above can be provided between these two connecting flanges, cf. Fig. 6 .

[0050] The elastic connecting element 15 can transmit the drive torque and deform to compensate for, for example, slight buckling movements of the roller.

[0051] To prevent uneven running or imbalance, a centering device 18 can center the output shaft of the spur gear drive relative to the roller, wherein such a centering device 18 can, for example, comprise a centering sleeve. Independently of this, the centering device 18 can extend axially over the elastic connecting element 15 and connect the roller-side connecting element 17 to the output shaft of the spur gear drive in a centering manner.

Claims

1. Agricultural machine comprising a pair of rollers (1) for processing crops, and a drive device for driving the mentioned pair of rollers (1) in a counterrotating manner, wherein the mentioned drive device comprises a spur gearing means which has a first spur gearing (5) having an uneven number of spur gears for driving a first roller (2) of the pair of rollers (1), and a second spur gearing (6) having an even number of spur gears for driving the second roller (3) of the pair of rollers (1), characterised by a common drive shaft (7) that is arranged offset from the rollers (2, 3) to be driven and is configured as a gearing input shaft, on which the two spur gearings (5, 6) are positioned with an input spur gear (10, 11) in each case.

2. Agricultural machine according to the preceding claim, wherein the first spur gearing (5) has precisely three spur gears, and the second spur gearing (6) has precisely two spur gears.

3. Agricultural machine according to either of the preceding claims, wherein the two spur gearings (5, 6) comprise two separate gearing housings (8, 9) which are sealed against one another and with respect to the surroundings.

4. Agricultural machine according to any of the preceding claims, wherein the spur gearings (5, 6) comprise separate lubricant reservoirs that are sealed against one another.

5. Agricultural machine according to any of the preceding claims, wherein the two spur gearings (5, 6) are pivotable relative to one another about a pivot axis which is arranged at least approximately coaxially with the common drive shaft (7).

6. Agricultural machine according to the preceding claim, wherein the spur gearing (6) having the smaller number of spur gears drives a, preferably upper, roller (3) that is suspended so as to be movable transversely to the roller longitudinal axis, and the spur gearing (5) having the larger number of spur gears drives a roller (2) that is mounted rotatably but in a stationary manner.

7. Agricultural machine according to any of the preceding claims, wherein the spur gearing (6) with the even number of spur gears is associated with a / the roller (3) that is suspended so as to be movable transversely to the roller longitudinal axis, in such a way that the mentioned roller (3) experiences a movement force, in the case of blockages or increasing drive resistance, by the drive forces of the mentioned spur gearing (3), which movement force is directed in a manner driving away from the other roller (2), and / or experiences a self-opening effect, wherein the movably suspended roller (3) is preferably arrange on the side of the input spur gear (11) of the mentioned spur gearing (6) on which the input spur gear (11) moves away from the other roller (2), in particular moves upwards.

8. Agricultural machine according to any of the preceding claims, wherein a suspension separate from the spur gearings (5, 6), for movable suspension of one of the rollers (3) and for carrying away bearing forces past the spur gearings (5, 6) is provided, wherein the mentioned suspension in particular comprises a pivot link arrangement (13) which mounts the mentioned roller (3) so as to be pivotable about a pivot axis which extends at least approximately coaxially to the common drive shaft (7).

9. Agricultural machine according to any of the preceding claims, wherein a hinged, preferably resiliently hinged, drive connection (14) is provided between at least one roller, in particular the roller (3) suspended so as to be movable transversely to the roller longitudinal axis, and the associated spur gearing (6), which drive connection is configured for transmitting drive torques and for compensating angular errors and / or axial offset between the output shaft of the spur gearing (6) and the roller (3).

10. Agricultural machine according to the preceding claim, wherein the mentioned hinged connection (14) comprises a resilient connection element (15) which is arranged between a connection element (16) that is rigidly connected to the output shaft of the spur gearing (6) and a connection element (3) that is rigidly connected to the roller (3), and which connects these two connection elements (16, 17) in a torque-transmitting manner in such a way that the mentioned connection element (15) experiences elastic deformation in the case of bending movements of the roller (3) relative to the output shaft of the spur gearing (6), wherein the resilient connection element (15) in particular forms a resilient, preferably rubber-elastic, plate or annular plate which is mounted between two connecting flanges which form the mentioned connection elements (16, 17).

11. Agricultural machine according to any of the preceding claims, wherein the output shaft of the spur gearing (6) is centred relative to the roller (3) driven by the spur gearing (6) by means of a centring device (18).

12. Agricultural machine according to any of the preceding claims, wherein the two spur gearings (5, 6) are axially offset relative to one another in the direction of the drive shaft (7) and / or are arranged on the same side of the pair of rollers (1) to be driven, wherein preferably the spur gearing (6) having the smaller number of spur gears is arranged so as to be spaced further from the front-face end of the pair of rollers (1) than the spur gearing (5) having the larger number of spur gears.

13. Agricultural machine according to any of the preceding claims, wherein a lower roller (2) of the pair of rollers (1) is mounted rotatably but in a stationary manner on a unit frame, and an upper roller (3) of the pair of rollers (1) is suspended so as to be movable in height, wherein the lower roller (2) is associated with the three-gear spur gearing (5) and the lower roller (3) is associated with the two-gear spur gearing (6).

14. Agricultural machine according to any of the preceding claims, which is configured as a conditioner for processing cut crops.