AGRICULTURAL EQUIPMENT WITH PTO DRIVE

Description

[0001] The invention relates to a trailed agricultural implement according to the preamble of patent claim 1.

[0002] Agricultural machinery can be supplied with rotary energy for its operation via a tractor's power take-off shaft. The rotary energy is preferably transmitted via a telescopic cardan shaft, which is equipped with a universal joint at each end. If the tractor's power take-off shaft and the agricultural implement's input shaft are aligned, the rotary movement of the PTO is transmitted evenly. It is known that when the cardan shaft rotates 360° around its central axis, with increasing angulation of the respective universal joints due to the cardan arrangement, irregularities and thus vibrations occur in the drive train. This can lead to premature wear or destruction of drive components. This irregularity manifests itself in different angular velocities at the input and output of the universal joint, which occurs in the form of a sinusoidal oscillation and consequently generates a pulsating torque.If you combine two universal joints, as is common on a drive shaft, and align their respective inner universal joint forks, the uneven torsional vibrations cancel each other out if both universal joints are angled the same. This creates synchronous rotation of the drive shaft between the input and output shafts. If both universal joints are angled in the same direction, this is called a W-bend arrangement of a drive shaft. If both universal joints are angled in opposite directions, so that the adjacent input and output shafts are parallel to each other, this is called a Z-bend arrangement. The rotational movement or angular velocity at the input and output of the drive shaft is then uniform.

[0003] If the imaginary extensions of the center axes of the tractor's PTO and the agricultural implement's input shaft, which are at an angle to each other, meet approximately at the center of the cardan shaft, the irregularities cancel each other out over one rotation of the cardan shaft. This special universal joint or cardan shaft arrangement, in which the universal joints of the cardan shaft are equally angled in the same direction, is called W-bend If the center axes of the tractor's PTO and the agricultural implement's input shaft are offset from each other but parallel, the universal joints of the intermediate drive shaft are also the same, but angled in opposite directions. Here, too, the irregularities of the respective universal joints cancel each other out during one rotation of the drive shaft. This special case of a universal joint or drive shaft arrangement is called Z-benddesignated.

[0004] Wide-angle universal joints are generally known in agricultural technology, where one or both universal joints of the universal joint are replaced by a single wide-angle joint. These wide-angle universal joints consist of a double universal joint, allowing deflections of up to 80°. However, in continuous operation, they are subject to significant component wear at sharp deflections, such as those encountered during sharp cornering.

[0005] European patent EP 2 172 092 B1 shows a soil tillage implement attached to a tractor by a connecting device and driven by the tractor's PTO. This soil tillage implement is supplied with rotational power by the tractor's PTO via a cardan shaft. The cardan shaft, which consists of two individual cardan shafts, is divided approximately halfway along its length by a movable intermediate bearing with a rotatable intermediate shaft. This movable intermediate bearing is arranged approximately at the level of a vertical pivot axis of the connecting device between the implement and the tractor, around which axis the implement pivots when the tractor corners and the connecting device is angled laterally. The vertical pivot axis of the connecting device is arranged approximately halfway between the tractor's PTO and the input drive shaft of the soil tillage implement.The movable intermediate bearing is arranged on the front and rear sections of the connecting device in such a way that the universal joints of the cardan shafts of the drive shaft train adjacent to the intermediate bearing are only angled by approximately half the pivot angle of the connecting device, enabling almost synchronous operation without any significant torsional vibrations of the entire cardan shaft train between the tractor and implement, even during extreme cornering. This increases the durability of the cardan shaft train. If the structural requirements for arranging the intermediate shaft at the same angle, approximately half an angle, between the tractor's PTO and the input shaft of the soil tillage implement are not met, different deflection angles arise in the cardan shaft train, which lead to irregularities and thus increased torsional vibrations of the cardan shaft train.From US 2004 / 070172 A1 or US 3 908 398 A, further soil tillage implements are known which are attached to a tractor and are supplied with rotational energy by a power take-off shaft of the tractor via a cardan shaft train.

[0006] US 2004 / 070172 A1 describes a second PTO shaft in a fixed Z-bend position, ie the bearing unit has an intermediate shaft and is arranged movably on or at the connecting device in such a way that the intermediate shaft, when the tractor is at an angle to the implement, brings the first PTO shaft into a W-bend position, but cannot bring the second PTO shaft into a Z-bend position.

[0007] The object of the invention is to provide a drive arrangement for a powered agricultural implement which enables an approximately uniform drive of the implement by the power take-off shaft of the tractor even at any distance of the articulation or pivot point of the connecting device between the tractor and the implement.

[0008] This problem is solved by the features of the characterising part of claim 1.

[0009] By dividing the drive shaft arrangement between the tractor and the agricultural implement into a first and a second drive shaft, these can be arranged such that, during the pivoting movement of the connecting device between the tractor and the agricultural implement, the first drive shaft forms a W-bend and the second drive shaft a Z-bend. The irregularities within the respective drive shafts cancel each other out. Advantageously and unexpectedly, this arrangement eliminates the need for a symmetrical length distribution between the first and second drive shafts in the drive train, since the respective drive shafts already run synchronously.

[0010] This means that the pivot point of the connection device between the tractor and the agricultural implement can be set almost arbitrarily.

[0011] According to the invention, a bearing unit with an intermediate shaft is arranged on or at the connecting device in such a way that the intermediate shaft, when the tractor is angled relative to the device, moves the first cardan shaft into a W-bend position and the second cardan shaft into a Z-bend position.

[0012] Ideally, the bearing unit, which is arranged on or on the connecting device, moves laterally relative to the connecting device, as viewed from the device toward the drive unit. When viewed from above, the bearing unit swings further away from the connecting device, the more angled the drive unit and the device are to each other.

[0013] Particularly advantageous is an at least largely parallel movement of the bearing unit or an intermediate shaft mounted therein relative to the alignment of the connecting device between the device and the drive unit. This parallel movement allows the input and output angles of the cardan shaft, which forms a W-bend, or its universal joint angle, to be aligned almost symmetrically. Likewise, the parallel movement of the bearing unit inevitably maintains the Z-bend, which forms the other cardan shaft in the cardan shaft train.

[0014] Preferably, the bearing unit moves in the opposite direction of the pivoting of the implement to the drive unit. This means: if the drive unit moves to the left relative to the implement, the bearing unit moves to the right. If the drive unit moves to the right, the bearing unit moves correspondingly to the left. This maximizes the possible steering or turning angle between the drive unit and implement, as the drive unit or its outer contour can pivot up to the connecting device, as the intermediate shaft or the bearing unit pivots away from the connecting device in the opposite direction.

[0015] Furthermore, an actuator is provided, which is connected to the bearing unit and controls the movement of the bearing unit relative to the connecting device. This can create a forced movement of the bearing unit.

[0016] The forced movement of the bearing unit can be controlled depending on the pivot angle between the device and the drive unit. Through a clever arrangement of the actuator, the movement of the bearing unit is almost synchronous with the pivoting movement of the device relative to the drive unit, as occurs, for example, when cornering with varying degrees of rigidity.

[0017] Advantageously, the actuator is also connected to an actuation mechanism for the steerable axles of the agricultural implement. This allows the position of the bearing unit relative to the connecting device as well as the steering angle of the implement's steering axles to be adjusted simultaneously, ensuring the implement follows the correct path behind the drive unit. A correct path, also known as forced steering, prevents soil and crop damage, as well as excessive stress on the implement's chassis components, which occurs during normal field and road travel, especially with high axle loads.

[0018] In particular, the actuator further comprises an additional connection to the drive unit and / or the agricultural implement. This can be designed as a mechanical strut, push or pull rod, or in the form of a hydraulic master-slave cylinder combination. This creates a positive-running mechanism that ensures optimal positioning of the bearing unit relative to the connecting device without any further intervention by the driver, in order to achieve the most uniform movement of the drive train possible.

[0019] In a specific embodiment of the invention, the actuator is designed as a servomotor. This can be a hydraulic or electric actuator connected to a hydraulic or electronic measuring device and / or a control and regulation unit, which determines geometric parameters such as the angular position or distances between the drive unit, connecting device, cardan shaft arrangement, bearing unit, and / or agricultural implement and controls the servomotor accordingly, particularly when cornering. The measuring device can provide progressive, degressive, or proportional control of the servomotor depending on the determined geometric parameters.

[0020] Furthermore, the actuator can be controlled as a servomotor by a control and regulation unit in conjunction with a measuring device for recording one or more irregularity parameters in the drive train depending on the measured parameters. The irregularity with which the shafts and joints of the drive train rotate can be determined by measuring one or more parameters such as the applied torque, angle of rotation, or the angular velocity of one or more components of the drive train. The drive train is considered the entire operative connection between the power take-off shaft of the drive unit and one or more driven work tools or auxiliary devices of the agricultural implement. In particular, cyclically fluctuating measured values ​​indicate a non-uniformity. Based on this, the servomotor can be controlled in such a way that the fluctuation of the measured values ​​decreases.Preferably, the measuring devices are arranged in the area of ​​the storage unit or integrated into it.

[0021] The invention is particularly characterized by dividing a cardan shaft drive train between the drive unit and the agricultural implement into at least a first and a second cardan shaft arrangement, which, when angled, each form approximately a Z-bend and a W-bend, respectively. Each of these arrangements, both individually and collectively, exhibits synchronous operation properties and enables a uniform, mechanical drive of the agricultural implement by the drive unit. This arrangement, unusual and unusual at first glance, enables an extremely robust drive train design, which ensures extreme torque and power transmission as well as maximum protection of all drive train components involved through the optimized synchronous operation of the cardan shaft train.

[0022] Further details and advantages of the subject matter of the invention will become apparent from the following description and the accompanying drawings, which illustrate an embodiment with the necessary details and individual parts. They show: Fig. 1: a perspective view of a tractor with an attached agricultural implement. Fig. 2: a view of a tractor with attached agricultural implement in plan view. Fig. 3: a view of a tractor with attached neighboring implement in side view. Fig. 4: an enlarged view analogous to Figure 2

[0023] Figure 1shows an agricultural implement 1, here a foldable rotary harrow with rotating soil tillage tools, which is laterally pivotably connected to a drive unit 3, for example a tractor, via a connecting device 2 designed as a drawbar and a coupling head 15. The coupling head 15 can be designed, for example, as a towing eye or ball head matching the trailer coupling of the drive unit and represent a detachable connection. A trailer coupling of the drive unit can, for example, be a pin coupling, a drawbar hook, a ball head, a field bar, or a three-point attachment head. The coupling head 15 enables additional degrees of freedom to compensate for uneven ground, excavation movements of the implement 1, etc., by lateral pivoting of the implement 1 relative to the drive unit 3, which usually occurs when cornering and during steering movements.The device 1 rests on the ground via a rigid or retractable chassis 13 with attached wheels 14, indicated here. If the drive unit 3, in this case the tractor, changes its direction of travel or travels along a curved path, the device follows the drive unit according to the distance between the drive unit 3 and the chassis 13. The angle between the drive unit 3 and the connecting device 2 or device 1 changes, as shown. The device is equipped with a gearbox 12, through which the drive power of the drive unit 3 is transmitted to the working tools of the device 1. In the case of a preferred rotary harrow, the drive power is transmitted from the gearbox 12 via a gear box 21 to several rotating rotary tines 22, which engage with the soil and mix or chop it.

[0024] The input shaft 10 of the transmission 12 is connected to the power take-off shaft 4 of the drive unit via a cardan shaft arrangement 5, consisting of a first cardan shaft 6, a second cardan shaft 7 and a bearing unit 8 arranged between the two cardan shafts and an intermediate shaft 16 mounted therein. The PTO shaft 4 is generally aligned in the longitudinal direction or direction of travel of the drive unit 3 and serves for the mechanical-rotary transmission of the engine power of the drive unit 3 to the attached or mounted implement 1. The first cardan shaft 6 is detachably connected at one end via a universal joint to the PTO shaft 4 of the drive unit and at its other end, likewise via a universal joint, to an intermediate shaft 16, which extends rotatably through the bearing unit 8.At each end of the bearing unit 8, which is preferably designed as a tube or hollow body, a ball, roller, or plain bearing is arranged, which fixes the intermediate shaft 16 translationally to the bearing unit. Beyond the bearing unit 8, the intermediate shaft ends in a shaft stub, which is connected to the universal joints of the adjoining cardan shafts 6, 7 via a key, profile, or pin pair in a torsionally rigid and preferably axially immovable manner. The intermediate shaft 16 is concealed by the bearing unit 8 and universal joints, but is indicated by its central axis of rotation. Between the bearing unit 8 and the gearbox 12, a further cardan shaft 7 is arranged, which is cardanically connected on one side to a universal joint on the intermediate shaft 16 of the bearing unit and on the other side to a universal joint on the input shaft of the gearbox.The cardan shafts are equipped with telescopic profiles which connect the respective universal joints of the cardan shaft 6, 7 to one another in a length-adjustable manner. The bearing unit 8 is mounted on the connecting device 2 by means of a further mechanism 20 so that it can be moved laterally relative to the connecting device 2. This mechanism 20 can, as shown, be implemented by a parallelogram joint arrangement. A sliding link or a simple pivoting lever is also conceivable. In the case of a simple pivoting lever, its pivot axis is aligned approximately parallel to the main extension direction 17 of the connecting device 2. This results in a lateral pivoting of the bearing unit 8 in an imaginary pivot plane which is perpendicular to the connecting device 2 or its main extension direction 17, for example in the form of an arc segment. The lateral movement of the bearing unit 8 orits connecting shaft 16 to the main extension direction 17 of the connecting device 2, wherein the main extension direction 17 generally corresponds to the direction of travel when the drive unit 3 and device 1 (not shown here) travel straight ahead.

[0025] The mechanism 20 for the lateral movement of the bearing unit 8 relative to the device 1 consists of two pivoting levers 18. The pivoting levers 18 are each pivotable relative to the connecting device 2 and are mounted, preferably in a parallelogram manner, with two parallel pivot axes and the bearing unit 8. An actuator 9 is articulated to a further attachment point 11 on the drive unit via an actuating arm 19 projecting laterally from a pivoting lever 18. If the drive unit 3 changes its position relative to the device 1 or the connecting device 2, the position of attachment point 11 to the coupling head 15 changes. As a result, the change in the position of point 11 is transmitted via the actuator 9 to the actuating arm 19 and the pivoting lever 18 and thus to the mechanism 20 for the lateral movement of the bearing unit 8, which then changes its position relative to the connecting device 2 together with its intermediate shaft 16.

[0026] Figure 2shows the arrangement with its essential components Figure 1 in top view.

[0027] The implement 1 is connected to the drive unit 3 in a laterally pivotable manner via the connecting device 2 and the coupling head 15, which is concealed by the cardan shaft 6. The pivot angle of the implement or its connecting device to the drive unit 3 is represented by the angle α based on the center planes, which run through the main extension direction 17 of the connecting device 2 and the power take-off shaft 4 of the drive unit 3. As already described above, the angle α causes the attachment point 11 to change its position relative to the connecting device 2 or the coupling head 15. Accordingly, the actuator 9 transmits this movement to the adjustment mechanism of the bearing unit 8. As a result, the bearing unit 8 moves laterally away from the connecting device 2, in each case opposite to the pivoting direction of the drive unit 3.The alignment of the intermediate shaft 16 and the main extension direction 17 are always parallel or at least approximately parallel to one another. The lateral offset of the bearing unit 8 or intermediate shaft 16 from the connecting device 2 or main extension direction 17 is represented by the distance a. If the drive unit 3 steers or pivots to the right in its direction of travel, as shown, the distance a of the bearing unit 8 from the connecting device 2 increases to the left with increasing pivot angle α. If the drive unit 3 pivots or steers to the left in the opposite direction, the bearing unit 8 shifts accordingly to the right of the connecting device 2. When the drive unit 3 travels straight ahead, the pivot angle α decreases to approximately 0°. Accordingly, the bearing unit 8 or intermediate shaft 16 moves towards the center of the connecting device 2.The lateral distance a of the bearing unit 8 to the connecting device 2 thus also runs, but in the opposite direction towards 0.

[0028] Figure 3 shows the arrangement of the device and drive unit 3 as well as their essential components in the pivoted-in state of the drive unit 3 in side view.

[0029] The connecting device 2 can be seen, which, with the coupling head 15, connects the device 1 to the drive unit 3 in an articulated manner so that it can be pivoted laterally in the direction of travel about an imaginary vertical axis. The actuator 9 is articulated between the fastening 11 and the outer end of the actuating arm 19. The vertically and parallel pivot bearing of the pivot lever 18 relative to the connecting device 2 or bearing unit 8 can be seen. The universal joint of the first cardan shaft 6, which is connected to the power take-off shaft 4 of the drive unit 3, is located approximately at the level of the coupling head 15 or its imaginary vertical axis. An arrangement of this type is typically found in a drive unit 3, shown here a tractor with a ball head or pin coupling. The other universal joint of the cardan shaft 6 is cardanically connected to the intermediate shaft 16 of the bearing unit 8.The other end of the intermediate shaft 16 is connected via another universal joint to the second drive shaft 7, which in turn is connected via another universal joint to the input shaft 10 of the gearbox 12. Below the gearbox 12, for the preferred form of a rotary harrow as device 1, a gear box 21 can be seen, to which rotating rotary tines 22 are attached. These tines are connected to the gearbox 12 via the gear box 21. Instead of a gearbox, any other type of countershaft or direct drive for a working tool or other device components are conceivable.

[0030] Ideally, the PTO shaft 4, the cardan shaft 6, the intermediate shaft 16, the cardan shaft 7 and the input shaft 10 run approximately through an imaginary horizontal plane, which runs parallel to the connecting device or its main extension direction 17. Thus, the deflection angle dependencies of the cardan shafts in plan view (compare Figure 2) can be reduced to a purely 2-dimensional task. However, different height differences between the power take-off shaft 4 and the input shaft 10 of the gearbox 12 are also possible. However, it is crucial that the respective cardan shafts are also angled in a W- or Z-bend in side view. Although this spatially entails an additional universal joint angle, the desired synchronization of the cardan shaft arrangement is still achieved, provided that the required conditions are met at least in the top view, as in Figure 2 described, must be complied with.

[0031] Figure 4 shows an enlarged view of the cardan shaft arrangement 5 from Figure 2with the respective bending angle dependencies. The cardan shaft 6 represents a W-bend arrangement and the cardan shaft 7 a Z-bend arrangement. The decisive factor for the synchronization of a cardan shaft, regardless of whether it is a W- or Z-bend, is that the input and output angles of the universal joints relative to the longitudinal axis of the cardan shaft are as equal as possible. Since the lateral displacement of the bearing unit 8 achieves an axially parallel displacement of the intermediate shaft 16 to the input shaft 10, a Z-bend is always created for the 2nd cardan shaft 7, in which the input angle γ1 between the cardan shaft 7 and the intermediate shaft 16 and the output angle γ2 between the cardan shaft 7 and the input shaft 10 continuously increase with increasing lateral overhang of the intermediate shaft 16 or bearing unit 8 relative to the connecting device 2, referred to here as distance a. The synchronization of the cardan shaft 7 is therefore always guaranteed by the Z-bend arrangement.

[0032] Due to this dependency, the lateral distance a can always be adjusted so that the output angle β2 between the cardan shaft 6 and the intermediate shaft 16 is approximately the same size and angled in the same direction as the input angle β1 between the power take-off shaft 4 and the cardan shaft 6. This puts the cardan shaft 6 in a W-bend arrangement with the same input angle β1 and output angle β2. Thus, by accepting an inherently unusual but intentionally adjustable Z-bend kinematics of a second cardan shaft 7, an optimized W-bend kinematics of the first cardan shaft 6 is achieved, although a non-uniform movement of the first cardan shaft would be expected due to the asymmetrical arrangement of the coupling head relative to the extension of the cardan shaft 6. LIST OF REFERENCE SYMBOLS

[0033] 1 Agricultural equipment 2 Connecting device 3 drive unit 4 PTO 5 Cardan shaft arrangement 6 First drive shaft 7 Second drive shaft 8 storage unit 9 actuator 10 input shaft 11 Fasteners 12 Gearbox 13 chassis 14 balance bike 15 Coupling head 16 Intermediate shaft, center axis of rotation 17 Main extension direction 18 Swivel lever 19 Actuating arm 20 Mechanism. 21 Gearbox 22 Rotary tines

Claims

1. A PTO-driven agricultural implement (1), preferentially PTO-driven soil cultivation implement, having a connecting device (2), preferentially a drawbar, for pivotably connecting the implement (1) to a drive unit (3), such as for example, a tractor, wherein the implement (1) is supplied with rotational energy via a PTO shaft (4) of the drive unit (3), wherein the transmission of the rotational energy between implement (1) and PTO shaft (4) takes place via a cardan shaft arrangement (5), which is assigned to the connecting device (2), wherein the cardan shaft arrangement (5) consists of at least one first (6) and a second cardan shaft (7), wherein between the first (6) and the second cardan shaft (7) a bearing unit (8) is arranged, which is moveably arranged on or at the connecting device (2), wherein the bearing unit comprises an intermediate shaft and is moveably arranged on or at the connecting device in such a manner that the intermediate shaft, in an angled position of the tractor relative to the implement, brings the first cardan shaft into a W-bend position and the second cardan shaft into a Z-bend position.

2. The agricultural implement according to Claim 1, characterised in that the bearing unit (8), seen from the implement (1) in the direction of the drive unit (3), with increasing pivoting (α) of the implement (1) or of the connecting device (2) relative to the drive unit (3), is moveably arranged laterally relative to the connecting device (2).

3. The agricultural implement according to Claim 1 or 2, characterised in that a movement of the bearing unit (8) takes place largely parallel to the orientation of the connecting device (2) between implement (1) and drive unit (3).

4. The agricultural implement according to any one of the preceding claims, characterised in that a movement of the bearing unit (8) relative to the connecting device (2) takes place opposite to the pivot direction of the implement (1) relative to the drive unit (3).

5. The agricultural implement according to any one of the preceding claims, characterised in that a control element (9) is provided, which is in connection with the bearing unit (8) and controls a movement of the bearing unit (8) relative to the connecting device (2) .

6. The agricultural implement according to Claim 5, characterised in that the control element (9) controls a movement of the bearing unit (8) relative to the connecting device (2) depending on the pivot angle (α) between implement and drive unit (3).

7. The agricultural implement according to Claim 5 or 6, characterised in that the control element (9) furthermore is in connection with a steering device, which actuates one or more steered axles of a chassis of the agricultural implement (1).

8. The agricultural implement according to any one of the Claims 5 to 7, characterised in that the control element (9) furthermore comprises an additional connection (11) to the drive unit (3) and / or to the agricultural implement (1).

9. The agricultural implement according to any one of the Claims 5 to 8, characterised in that the control element (9) is designed as a servomotor and in that a control and regulating unit with a measuring device for detecting geometrical position parameters of the connecting device and / or of the cardan shaft arrangement (5) or its drive train components (4, 6, 7, 8, 10, 12, 16, 21) arranged thereon is provided, wherein the control element (9) can be controlled by the control and regulating unit depending on one or more of the detected position parameters.

10. The agricultural implement according to any one of the Claims 5 to 9, characterised in that the control element (9) is designed as a servomotor and in that a control and regulating unit with a measuring device for detecting one or more irregularity parameters in the cardan shaft arrangement (5) or adjoining drive train components (12, 21) is provided, wherein the control element (9) can be controlled by the control and regulating unit depending on one or more irregularity parameters.