EP2440030A1

EP2440030A1 - Bearing device at an agricultural machine

Info

Publication number: EP2440030A1
Application number: EP10786442A
Authority: EP
Inventors: Crister Stark
Original assignee: VAEDERSTAD-VERKEN AB; VAEDERSTAD VERKEN AB; Vaderstad Verken AB
Current assignee: Vaderstad Holding AB
Priority date: 2009-06-12
Filing date: 2010-05-28
Publication date: 2012-04-18
Also published as: WO2010144025A1; EP2440030A4; SE0950454A1; SE534357C2

Abstract

The invention relates to a bearing device (11, 50, 70) at an agricultural machine (1), which device comprises a bearing casing (19, 20, 51, 74, 75), a space adapted for a beam (12, 52, 73) extending through the casing, and at least one bearing element (23, 56, 76) arranged in the other space in the casing, which element preferably comprises circular- cylindrical rods of an elastic material, such as rubber. At least one beam stop member means (39, 40, 41, 54, 86, 87) is arranged to limit the rotary motion of the casing (19, 20, 51, 74, 75) in at least one predetermined direction of rotation.

Description

BEAIONG DEVICE AT AN AGRICULTURAL MACHINE

The present invention relates to a bearing device at an agricultural machine according to the preamble of claim 1.

BACKGROUND AND PRIOR ART

During a very long time agricultural machines have had resilient working means. Since a couple of decades it has been more and more common to build in different kinds of rubber suspensions in agricultural machines. See for instance WO 88/04133. Often, it is the question of a kind of a rubber suspension having a square inner portion and a square outer portion. These portions are normally turned 45° in relation to each other. Four rubber rods are mounted in the four corner spaces formed between the inner portion and the outer portion. This is a kind of rubber suspension which was invented by Hermann Neidhart from Switzerland in the nineteen-forties (GB 652266) and which is still used to a large extent. A rubber suspension of the kind defined in the preamble of claim 1 is known through DE 1755250. Rubber suspensions are very suitable in agricultural machines, when a rubber suspension constitutes a link, a resilient member as well as a shock absorber in one and the same machine element. This machine element has a very long life also in a difficult working environment.

At a conventional seed drill it is suitable to provide the drill coulters with rubber suspensions to get a good biasing and also have motion space to take up the irregularities of the ground. A problem is that the working means are not fixed, in this case drill coulters, when they are raised from the ground and the machine is transported on roads which often has a low standard. When the rubber suspensions assume a position near the idle position, the position of the drill coulters will not be distinctly defined and they are differently positioned, which does not look well from an aesthetic point of view. They also bang during transport in an unsatisfactory manner. Some manufacturers have solved this problem by beams acting as stop members which catch the drill coulters, which are pressed against these beams with a certain biasing. These beams give a good guide control and the drill coulters are kept both aligned and steady, but the solution is not practical and involves considerable costs. It is especially troublesome when the suspensions must have a short length in the axial direction because of lack of space. If the rubber suspension is short, it will be exceptionally instable for those drill coulters which are arranged on the outer sections of the machine, which during transport are turned up about 90°. Another problem is the one prevailing at different kinds of working means which are to cultivate the soil, for example cultivating tines. These ones must often have a heavily biased but resilient construction to be able to turn aside when they hit stationary hindrances, such as stones, tree roots or other objects in the ground. This resilient construction often implies that a helical spring or a hydraulic cylinder has been included in the attachment device of the working means. This resilient construction is often called "stone release" and must have such a high biasing that it does not spring back for the normal soil resistance. A problem is that the stone release may cause damages on the agricultural machine.

PROBLEM APPROACH

The object of the present invention is to provide a bearing device at an agricultural machine of the kind mentioned in the preamble, which device solves the problems mentioned above.

DISCLOSURE OF THE INVENTION

The object is reached with a device at an agricultural machine, which bearing device has the characterizing features of claim 1.

Preferred embodiments of the bearing device according to the invention have the characteristics set forth in the sub-claims.

On the whole, the problem is solved without any costs by constructing the outer casing of the suspension in such a way that stop members are formed, preferably six ones. These stop members are designed in such a way that they will become active at some degree before the idle position so that a small biasing is then obtained. This implies that the working means are hanging in a entirely straight line and that they are completely stable in this position. If said stop members are designed such that six stop members run against the inner beam simultaneously, it gives a very good stability in different planes. The same solution may be used also for a square rubber suspension. This is especially advantageous for short rubber suspensions and when outer sections are turned up.

In addition, to allow the drill discs to raise so much that they may pass over stones, it is advantageous to use a rubber suspension having a triangular shape so that it may be turned to maximally about 40 to 45°. At a square rubber suspension, the maximal elastic deflection is about 30°. A suspension in a triangular shape functions excellently in this application. The reason to it functioning so well is that if one builds a suspension in a triangular shape, it has a much lower hysteresis than a suspension with a square shape, i.e. the force needed to turn the suspension will to a larger extent return at the compression of a triangular design than of a design with a square cross-section. It must also be so durable and resistant to wear that it is not worn to any considerable extent at driving over stony areas, which makes it extra expensive. Often, this "stone release" need to be able to yield the working device in the order of 25 to 30°. A common biasing force may be 200 to 400 kp measured in the lowest part of the working means, i.e. its tip.

For cultivation, the problem is solved by utilizing the technique with a rubber suspension which may be biased to a certain extent so that an effective "stone release" is achieved, which is silent and wear resistant. In that connection it may also be manufactured at very competitive costs.

BRIEF DESCRIPTION OF DRAWINGS

The invention will below be described more in detail with reference to the accompanying drawings, which show a preferred embodiment.

FFiigg.. 11 shows a partial perspective view of an agricultural machine with a first embodiment of a bearing device according to the invention.

Fig. Ia shows a partial perspective view of a portion of the agricultural machine in

Fig. 1 and illustrates clearly in a perspective view the device of the invention according to Fig. 1. FFiigg.. 22 shows a partial side view of the agricultural device in Fig. 1 with the bearing device according to the invention of Fig. 1.

Fig. 2a shows a partial side view of a portion of the agricultural machine in Fig. 1 and illustrates clearly from the side the bearing device of the invention according to Fig. 1. FFiigg.. 33 shows a partial side view of a drill coulter in a raised position with the bearing device of the invention according to Fig. 1.

Fig. 4 shows a partial side view of a drill coulter in a working position with the bearing device of the invention according to Fig. 1.

Fig. 5 shows a partial exploded side view of a drill coulter with the bearing device of the invention according to Fig. 1.

Fig. 6 shows a side view in a larger scale of the bearing device of the invention according to Fig. 1 in a loaded condition. Fig. 7 shows a side view in a larger scale of the bearing device of the invention according to Fig. 1 in a unloaded condition.

Fig. 8 shows a side view in a larger scale of the outer casing of title bearing device of the invention according to Fig. 1.

Fig. 9 shows a side view in a larger scale of a second embodiment of a bearing device of the invention in an unloaded condition.

Fig. 10 shows a side view of a cultivator tine with a bearing device according to the invention corresponding to the embodiment of Fig. 1 - 8.

Fig. 11 is a schematic side view of a portion of an agricultural machine with an additional embodiment of a bearing device according to the invention.

Fig. 12 is a schematic side view similar to that of Fig. 11, where the front drill coulter has hit an object in the ground.

Fig. 13 is a side view of a drill coulter in a lower end position.

Fig. 14 is a side view of a drill coulter in an upper end position.

DESCRIPTION OF PREFERRED EMBODIMENTS

The same parts/details of the embodiments described and illustrated in the drawings have got the same designation numerals. This is essentially true for the embodiment of the bearing device shown in Figs. 1 to 8, as well as Fig. 10. In Fig. 9 and Figs. 11 to 13 other embodiments of the bearing device of the invention are shown.

In Figs. 1 and 2 an agricultural machine 1 is shown, where one of the side sections and the middle section are in a working position. The agricultural machine 1 has a frame 2 resting on a number of wheels 3 journalled in the frame, a container 4 for seed, fertilizers or any other spreadable material and a number of drill coulters 5, which via flexible hoses (not shown) are connected to a distributor 6, which via a standpipe 7 is connected to the container 4.

The agricultural machine 1 have drill coulters 5 mounted in three sections 8, 9, and 10, of which the side sections 8 and 10 are rotatable between a vertical transport position, such as the side section 10, and a horizontal working position, see the side section 8. The middle section 9 may be vertically raised between a position with engagement with the ground and an unengaged position. This motion may be used either during transport when the side sections are turned up or for instance at the headlands when the side sections 8 and 19 are lowered. In Fig. Ia a first embodiment of a bearing device 11 or a rubber suspension according to the invention is shown in a larger scale for the attachment of a predetermined number of drill coulters 5 to a transversal beam 12, seen in the driving direction in the working position, of the agricultural machine 1. A transversal beam 12 is arranged for each section 8, 9, and 10, respectively. The bearing device 11 will be described more in detail with reference to Figs. 6 to 8.

In Figs. 3 and 4 a drill coulter unit is shown in a transport position and a working position, respectively. In Fig. 5 the parts belonging thereto are shown more distinctly in an exploded view of a device 11 according to the invention with a drill coulter unit 13 comprising a somewhat curved arm 14, a cantilever 16 attached to the arm, on which cantilever the drill coulter 5 is journalled, and a pressure wheel 17 journalled in the end of the arm, with a scraping device 18 cleaning the tread of the wheel 17. At the other end of the arm, which is positioned at the bearing device 11 , a first bearing half 19 of a bearing casing is attached, preferably by welding. The bearing casing has a second bearing half 20. The bearing halves 19 and 20 are screwed together by means of screws 21 and bolts 22 through holes 22 (see especially Fig. Ia) through flanges 19a, 19b and 2Oa₅ 20b, respectively, arranged on the bearing halves. The designation numeral 24 refers to a tube with a sowing device, which is connected to each drill coulter 5. A flexible hose, not shown, is from the distributor 6 in Fig. 1 and 2 connected to each tube 24. Elastic, circular-cylindrically shaped rods 23, preferably of rubber, are arranged between the bearing halves 19, 20 and the beam 12 (see especially Figs. 6 and T). At least one lifting arm and at least a motion limiting arm 26 are attached to each beam 12, preferably by welding. The end of the lifting arm 25 which is facing away from the beam is journalled at one end of a hydraulic assembly (see especially Figs. 3 and 4), the other end of which is journalled in the frame 2 of the agricultural machine (see especially Figs. 1 and 2). The end of the motion limiting arm 26 facing away from the beam 12 is journalled at an L-shaped arm 28, the other end of which is journalled in the frame 2 of the agricultural machine 1. A depth stop in the form of a motion limiting rod 29 is journalled in the centre of the L-shaped arm, which rod is inserted into a recess in a portion of the frame 2. The other end of the rod is threaded and has a stop nut which is threaded together with a stop member 31. As is best shown in Fig. 4, the stop members 4 are intended to abut against surfaces 32 associated with the frame 2 to limit the downward movement of the drill coulters, when the piston assemblies 27 press the drill coulters 5 down below the ground surface into the soil in the working position. From Fig. 3 it is apparent that the rod 29 of the depth stop is in its entirely raised position, when the drill coulter unit is in its transport position. In Figs. 6-8, the first embodiment of the bearing device 11 of the invention is shown in a larger scale. In Figs. 6 and 7, the bearing device 11 of the invention is shown in a working position and in a transport position, respectively. In the bearing half 19, two flaps 34 and 35 have been cut and bent towards its inner side 36. In a corresponding manner, a flap 37 has been cut and bent towards the inner side 38 of the bearing half 20. In this way, the end surfaces 39, 40 and 41, respectively, of the flaps 34, 35 and 37 form stop members, which are arranged, in a limit position to abut against the outer surface 42 of the beam 12. Flaps of the kind shown in the drawings are also arranged at the opposite side (not shown) of the bearing halves 19, 20 so that, in this embodiment of the bearing device 11 , the number of stop members 39, 40, 41 is totally six, three on each side of the bearing halves with each drill coulter unit 13. This also results in a good balance at the rotation of the arm 14, so that the stop members 39, 40, 41 hit the beam 12. From Fig. 8, which shows only the outer bearing casing with the halves 19, 20, it is more apparent how the flaps 34, 35 and 37 have been cut and bent inwardly towards the centre of the bearing 19, 20. hi the position shown in Fig. 7, the stop members abut against the outer surface 42 of the beam 12, and in the position shown in Fig. 6, the drill coulter 5 has been pressed upwards in the working position, e.g. by a stone or any other obstacle in the ground, so that the rubber rods 23 are pressed together and the stop members 39, 40, 41 are released from their abutment against the outer surface 42 of the beam 12.

In the transport position, shown in Fig. 3, the stop members 39, 40 and 41 abut against the outer surface 42 of the beam 12, which is more apparent from Fig. 7. In the working position shown in Fig. 4 the rubber rods 23 are tensioned, i.e. somewhat compressed, which is more apparent from Fig. 6, in order to give the drill coulter 5 and the pressure wheel 17 a suitable pressure so that the drill coulter 5 permeates into the ground and so that a sufficient pressure lies on the pressure wheel in order to reclose the furrow. In this position, the depth stops together with the stop members 31 are inactive, and the motion limiting rods 29 are in the lowest position. As the stop members 39, 40, 41 do not abut against the beam 12, the bearing casing including the bearing halves 19, 20 andlience also the arm 14 may freely rotate to and fro.

In Fig. 9, a second embodiment of a bearing device 50 according to the invention is shown. In this case, the bearing consists of only one casing 51, which in cross-section is substantially square, through which casing a beam 52 extends which has an essentially square cross-section, corresponding to the beam 12 of the first embodiment. Four flaps 53 with stop members 54 have been cut and bent inwards towards the centre of the casing 51 so that they, in the position shown in Fig. 9, abut against the outer surface 55 of the beam 52. Circular-cylindrically shaped rods 56 of an elastic material, preferably rubber, have been mounted in the spaces formed at the inner corners 57 of the casing 51 between the casing 51 and the beam 52. The advantage with this embodiment is that it is much more hardwearing as the bearing is integral. It is, however, more cumbersome to mount, as both the beam 52 and the elastic rods 56 are to be inserted into the casings 51.

The number of flaps 53 arranged at the outer casing 51 of the bearing is dependent on the cross-section of the beam 52. Also here, the same number of flaps 53 with stop members 54 has been arranged at the opposite side of the casing 51, so that the number of stop members 54 with each drill coulter unit amounts to eight. At a beam with a square cross section, such as the beam 52 in Fig. 9, it may be sufficient with only two flaps at each side of the bearing casing 51. Each flap pair 53 is then arranged to abut with their stop members 54 against two opposite outer surfaces 55 of the beam 52.

The embodiment of the bearing device 11 according to the invention shown in Figs. 1 to 8, would also imply a solid casing, which is integral and which is substantially triangular in cross-section.

Fig. 10 shows a bearing device 11 according to the invention, the construction of which corresponds to the bearing device according to the first embodiment in Figs. 1 to 8, but is mounted as a holder for a working means, such as a cultivator tine 60 of an agricultural machine. In this case, the bearing consists of two bearing halves 19, 20 having a substantially triangular cross-section, through which bearing a beam 12 with an essentially square cross-section extends, which thus corresponds to the beam 12 of the first embodiment. The cultivator tine 60 is fixed, suitably by welding, to the bearing half 20. Three flaps 34, 35 and 37 with stop members 39, 40 and 41, respectively, have been cut and bent inwards towards the centre of the halves 19, 20, so that they in the position shown in Fig. 10 abut against the outer surface 42 of the beam 12. The circular- cylindrical rods 23 of an elastic material, preferably rubber, have been mounted in the spaces formed at the inner corners of the halves between the halves 19, 20 and the beam 12. The rubber resilient rods 23 of the bearing devices here result in a biasing which implies that the cultivator tine 60 may yield. It is evident that it is biased (about 10°) but may yield more when a stone is hit, about 30 to 35°. The construction is silent and durable and affords the cultivator tine 60 a good angle stiffness towards the frame of the machine, when the elasticity has a length extension of 150 to 250 mm. The triangular beam is a part of the frame construction of the machine at the same time as it supports working means. The number of working means or cultivator tines, which are mounted on at least one transverse beam 60, may amount to about 50, or more or less, depending on kind, field of application and machine size. By utilizing the technique with a rubber suspension which may be biased to a certain extent, a cultivator tine may be obtained, which at a "stone release" is silent and is almost impossible to wear out. It may also be manufactured at very competitive costs. In order to get the resilience at the "stone release" to function well it must be optimized. An important optimization is that it may be manufactured such that the force at the tip of the working means is not increased more than absolutely necessary, as too high a force when passing over hindrances tends to strain on the tip and its attachment so that fractures may occur.

In Figs. 11 to 14, an improvement of a bearing device 70 according to the invention is shown, where the bearing device 70 or the rubber suspension is provided with stop members in the two directions of resilience. Above, bearing devices have been described with resilience in only one direction of rotation. With stop members in both rotations of direction the end positions may be predetermined in the two directions of resilience, i.e. one gets an upper and a lower stop member.

In Figs. 11 and 12, two sowing units 71 and a following press wheel unit 72 are shown. For the sake of clarity, several details have either been deleted or only indicated with dash dotted lines, such as the link systems between the sowing units 71 and the press wheel units 72. Each such sowing unit 71 represents a row of similar sowing units which by means of bearing devices 70 are attached to beams 73 with a triangular cross- section. Rods 76 of an elastic material, such as rubber, are arranged between each beam 73 and bearing halves 74 and 75 of bearing devices 70 arranged thereon. The bearing halves 75 and 76 are screwed together by screws 77 and bolts 78 through holes through flanges 74a and 75a, respectively, and arranged on both sides of the bearing halves.

One bearing half 75 of the bearing device 70 is fixed, preferably welded, to an arm 79, at the other end of which a freely rotatable sowing disc 80 is journalled and is provided with an associated drill coulter device 81, which is screwed to the lower end of the arm 79 and has a lower opening 82 ending at the lower periphery of the sowing disc 80. As is shown in Fig. 11, the sowing discs of the two rows are mounted at different sides of the arm 79. Flexible tubes, not shown, run from the drill coulter device to a device for storage, dosage and distribution of seed or fertilizer. A double flap 83 has been cut in the bearing half 74 and bent towards the centre of the bearing device 70. Two flaps 83 have been cut in the bearing half 75 and bent towards the centre of the bearing device 70. The double flaps 83 are substantially U-shaped and have a web each which is connected to the respective bearing half 74 and 75 and two legs 84 and 85 with one stop member 86 and 87, respectively, each at the end of the leg (see Figs. 13 and 14). Each double flap 83 has subsequently an stop member 86 and an stop member 87, where one stop member 86 is arranged to define the transport position forwards (see Fig. 13), and the other stop member 87 defines the motion of the sowing disc backwards (see Fig. 14), for example when it has hit a hard object 88 in the ground such as a stone. The ground level is indicated with the designation numeral 89. hi Fig. 12, the front sowing disc has encountered an object at the ground level 89, and the sowing disc and the arm 79 are forced upwards to an end position, where the stop members 86 of the double flaps 83 have come to abutment against the beam 73.

In Fig. 13, the sowing disc is in its lower permitted working position and in Fig. 14 the suspension is tensioned just over 40° in relation to the position in Fig. 13 and there the sowing disc 80 reaches its upper permitted position.

The bearing device 70 is without any stop member action symmetric with a resilient force near zero in the idle position. As the bearing device 70 in the normal case is symmetrically designed, substantially the same resilient characteristic is obtained in both tension directions. Then, it is evident that the double flaps 83 with the stop members 86, 87 may be formed such that a given angle region is chosen, within which the bearing devices 70 may be permitted to work, e.g. from -17° to +40° or any other angle region desired within the conceivable working region. The bearing device 70 is advantageously given a symmetric shape, but to meet special requirements on resilient characteristic it may also be given an unsymmetrical shape. It is also suitable to provide the opposite side of the bearing device with corresponding stop members to obtain a balance when the stop members 86, 87 hit the outer surface 73a of the beam 73. Advantageously a double flap 83 may be arranged for each longitudinal side of the beam 73, i.e. three double flaps 83 with a triangular beam 73, four with a square beam, etc.

A lower and an upper position may be practical, for example as it often is lack of space in machine constructions and as machines are driven on irregular and stony grounds. The irregular ground and different kinds of stones give large motion to the working means, such as the sowing discs. Then, it is possible distinctly to define which region of motion a working means shall have. In this way, one may avoid that the discs and other parts hit against other parts of the agricultural machine at the same time as the function of the machine may be optimized.

The device according to the invention is in its construction not limited to those embodiments shown in the Figs. 1 to 14 but may be modified within the scope of the accompanying claims. For example, the number of the flaps may be varied depending on tiie cross-section of the transversal beam. The stop members may be adjustable by each comprising a threaded rod, which is screwed into a threaded hole in said bearing casing. The stop members may also be fixed to the bearing casing preferably by stop member parts welded to the inner side. Also the number of drill coulters may be varied and the bearing device is, of course, not limited to the agricultural machines shown but may be used on other machines, such as a machine without rotatable side sections. The elastic bars are favourably circular-cylindrical but may have another cross-section, such as square, triangular or any other suitable shape.

Claims

1. A bearing device (11, 50, 70) at an agricultural machine (1), which device comprises a bearing casing (19, 20, 51, 74, 75), a beam (12, 52, 73) extending through the casing, at least one bearing element (23, 56, 76) arranged in the space between the casing and the beam, preferably including circular-cylindrical rods of an elastic material, such as rubber, and at least one stop member means (39, 40, 41, 54, 86, 87) arranged on the bearing casing ( 19, 20, 51 , 74, 75), characterizedin that said at least one stop member means (39, 40, 41, 54, 86, 87) is arranged to abut against the outer surface (42, 55, 73a) of the beam (12, 52, 73) in question in order to limit the rotary motion of the casing (19, 20, 51, 74, 75) in a predetermined direction of rotation.

2. A device according to claim l,characterizedin that said at least one stop member means (39, 40, 41, 54, 86, 87) is arranged on the two axial outer sides of the bearing casing (19, 20, 51, 74, 75).

3. A device according to claim 1 or claim 2, characterizedin that said at least one stop member means (39, 40, 41, 54, 86, 87) is arranged on the casing (19, 20, 51, 74, 75) for abutment against the outer surface (42, 55, 73a) of the beam (12, 52, 73) in question.

4. A device according to any of claims Ito3, characterizedin that said at least one stop member means (39, 40, 41, 54, 86, 87) is integral with the casing (19, 20, 51) preferably by cutting and bending to form flaps (34, 35, 37, 83) turned inwards with stop members (39, 40, 41, 54, 86, 87) arranged at the ends.

5. A device according to any of claims 1 to3,characterizedin that said at least one stop member means is adjustable by each comprising a threaded rod, which is screwed into a threaded hole in said casing (19, 20, 51, 74, 75).

6. A device according to any of claims Ito3,characterizedin that said at least one stop member means is fixed to the casing (19, 20, 51, 74, 75) through stop member means which are preferably welded to the inner side.

7. A device according to any of claims 1 to 6, characterizedin that said casing (19, 20, 51, 74, 75) is arranged to be mounted on an intended beam (12, 52, 73) with a substantially triangular or substantially square cross-section, wherein the number of stop member means (39, 40, 41, 54, 86, 87) is six and eight, respectively.

8. A device according to claim Ito7, characterizedin that said at least one stop member means (39, 40, 41, 54, 86, 87) is arranged on the casing in such a way (19, 20, 51) that when the stop member means abuts against the outer surface of the beam (12, 52, 73) a certain biasing prevails in said bearing elements (23, 56, 76).

9. A device according to claim 8, characterizedin that said bearing elements (23, 56, 76) may be biased by said at least one stop member means (39, 40, 41, 54, 86, 87) being brought to abutment against the beam (12, 52, 73) in a predetermined position before each of said bearing elements reaches its idle position.