CRACKER TRACK

Description

[0001] The invention relates to a tracked undercarriage of an agricultural machine with a drive wheel according to the preamble of claim 1.

[0002] Agricultural machinery, such as tractors or self-propelled harvesters, is becoming increasingly larger and more powerful to enable more efficient cultivation of agricultural land. As the machinery's own weight increases, so does its permissible total weight, which must be supported on the ground. A higher total weight often allows for significant ballasting of the agricultural machinery, which can be variably positioned depending on the task at hand, for example, to influence the machine's center of gravity. To minimize adverse soil compaction, it is desirable to increase the contact area with the ground. With pneumatic tires, an increasing contact area also necessitates a larger tire diameter, thus increasing the required installation space.

[0003] Therefore, tracked undercarriages with a large contact area due to their design are increasingly being used, for example, those featuring a track made of an elastic material such as rubber. The tracked undercarriage typically includes a drive wheel for, for example, force- or friction-driven propulsion of the track, as well as at least one running wheel and support rollers positioned between them. A disadvantage of using such tracked undercarriages is the potential impairment of power transmission between the drive wheel and the track by friction-reducing materials such as dirt, mud, clay, or other contaminants.

[0004] To reduce this contamination, a drive wheel is known, for example, from EP 3 415 407 A1, which has radially spaced friction surfaces for power transmission from the drive wheel to the track and recesses for the removal of contaminants. These recesses allow contaminants located between the drive wheel and the track, which impair power transmission, to be removed. In cases of particularly heavy contamination, for example, when or after the track has partially sunk into a wet, soft surface, it may not be possible to reliably remove the contaminants. A damp or contaminated surface of the friction surfaces or the inner side of the track, with which the friction surfaces interact, can lead to increased slippage between the friction surfaces of the drive wheel and the track.

[0005] A crawler track system with the above-mentioned characteristics is also known from US 2002 / 167222 A1.

[0006] It is therefore an object of the invention to avoid the described disadvantages of the prior art and in particular to significantly reduce the slippage occurring between the drive wheel and the track.

[0007] This problem is solved according to the invention by the characterizing features of claim 1.

[0008] According to claim 1, a tracked undercarriage of an agricultural machine is proposed, comprising a drive wheel for driving an elastic tracked track, wherein friction elements for force-locking interaction with the tracked track are arranged radially outside on the drive wheel, in particular detachably, wherein at least one wear-resistant element is arranged radially outside on the drive wheel adjacent to at least one friction element.

[0009] The invention has many advantages. The at least one wear-resistant element is also designed and configured for positive engagement with the track. Compared to the friction element, the at least one wear-resistant element exhibits greater dimensional stability. This results in improved positive transmission of the driving force from the drive wheel to the elastic track, particularly in slippery environments. Because the wear-resistant element has greater dimensional stability than the friction element, its sharp edges have a cleaning effect on the inner surface of the rubber track when they come into contact with it. Furthermore, the increased dimensional stability causes the wear-resistant elements to press deeper into the inner surface of the track, thus enabling better power transmission.To avoid excessive wear on the track belt caused by the wear-resistant elements, additional friction elements are arranged radially on the outside of the drive wheel alongside the wear-resistant elements. These friction elements have lower dimensional stability and therefore act less abrasively on the track belt.

[0010] According to the invention, at least one wear-resistant element has greater strength than the friction elements. This results in the wear-resistant elements being more dimensionally stable than the friction elements.

[0011] Another advantageous embodiment provides that at least one wear-resistant element is made of metal, in particular aluminum. Aluminum, in particular, has proven especially advantageous for transmitting the driving force from the drive wheel to the track. Preferably, the friction elements consist of an elastomer, in particular rubber.

[0012] According to the invention, the drive wheel comprises two rims arranged axially side by side, each rim comprising friction elements and at least one wear-resistant element, the friction elements and the at least one wear-resistant element of each rim extending axially across the entire width of the respective rim. This enables the track to be guided between the rims by means of guide blocks, and the axial extension of the friction elements and wear-resistant elements across the entire width of the respective rims allows for a particularly effective transmission of the drive force to the track.

[0013] According to a further advantageous embodiment, the drive wheel can comprise a plurality of friction elements and wear-resistant elements arranged alternately in the circumferential direction of the drive wheel, wherein preferably a wear-resistant element is arranged next to each pair of adjacent friction elements, and further preferably the friction elements and wear-resistant elements are arranged alternately with each other, such that a wear-resistant element follows each friction element in the circumferential direction of the drive wheel. Iterative tests have shown that an alternating arrangement, and in particular an alternating arrangement, of the friction elements is especially suitable for preventing slippage between the drive wheel and the track.

[0014] A wear-optimized design stipulates that only the drive wheel of the crawler track includes wear-resistant elements for interaction with the crawler track.

[0015] Preferably, the wear-resistant elements can have a profile on their contact surface interacting with the track, the profile preferably comprising a plurality of grooves so that moisture or contaminants present in the area of ​​the contact surface between the track and the wear-resistant elements can escape through the grooves. The friction elements can also have a profile.

[0016] Further advantageous embodiments are the subject of further dependent claims and are described below with reference to an exemplary embodiment illustrated in several figures. These show: Figure 1: A schematic view of an agricultural machine with two crawler tracks according to the invention; Figure 2: A perspective view of one of the crawler tracks of the machine according to the invention. Figure 1 Figure 3: A perspective view of a main wheel of the crawler track according to Figure 2 .

[0017] One embodiment, which is described in the Figures 1 to 3 The illustration shows a crawler track 1 according to the invention, as it can be used, for example, in an agricultural machine 2, which is in Figure 1 The agricultural machine 2 is a forage harvester, used to harvest crops growing on a surface 7. However, the agricultural machine 2 can also be configured as a tractor or combine harvester. The machine 2 is equipped with two crawler tracks 1, each located on opposite sides of the machine 2. The crawler tracks 1 are particularly well illustrated by the following: Figure 2 . In the following, only one of the caterpillar tracks 1 will be described in detail.

[0018] The crawler track 1 comprises two opposing main wheels 3, 4, arranged one behind the other in the longitudinal direction of the crawler track 1 and each rotatable about a central axis of rotation 9, 10. The main wheels 3, 4 are spanned by a closed elastic track 5. In the example shown, the rear main wheel 4 is designed as an actively driven drive wheel 11, so that the machine 2 can be moved on the surface 7 by means of the crawler track 1. The crawler track 1 also includes two auxiliary wheels 13, which are arranged between the main wheels 3, 4 in the longitudinal direction of the crawler track 1. The auxiliary wheels 13 are assigned to a ground section 15 of the track 5, where the ground section 15 designates the section of the track 5 that is in direct contact with the surface 7 during normal operation of the machine 2.The auxiliary wheels 13 serve to transfer loads to be carried by the crawler tracks 1 into the subsoil 7, whereby in the interaction of the auxiliary wheels 13 with the main wheels 3, 4 a contact area created is considerably increased compared to a normal round wheel and thus a surface pressure of the subsoil 7 is reduced.

[0019] In the example shown, the main wheels 3, 4 are each formed by two rims 16, which in turn are each formed by a plurality of rim segments 14. This is particularly evident from the following: Figure 3The rims 16 of each main wheel 3, 4 are arranged side by side in the lateral and axial direction of the track 1. The rim segments 14 of each rim 16 extend radially outwards in a spoke-like manner relative to their respective axis of rotation 9, 10. In the example shown, each rim segment 14 comprises two radially outer guide sections 6, by means of which the track 5 can be guided along the circumference of the respective main wheel 3, 4. The guide sections 6 of the main wheels 3, 4 are each equipped with a transmission unit 8, which is arranged on the respective rim segment 14 in a force-transmitting manner. In the example shown, this is achieved by screwing the respective transmission unit 8 to the corresponding rim segment 14, whereby – as can be seen in particular from the Figure 3This results in the transmission units 8 each comprising two bolt-shaped fastening means 17, which can be guided through associated recesses in the rim segments 14 and screwed onto a wheel-side inside of the respective rim segment 14.

[0020] The transmission units 8 of the drive wheel 11 comprise friction elements 18 and wear-resistant elements 19. In the example shown, the friction element 18 is made of rubber, and the wear-resistant element 19 is made of aluminum. The friction elements 18 and the wear-resistant elements 19 come into direct contact with the inner surface 22 of the track 5 and thus serve to transmit force from the drive wheel 11 to the running belt 5. For the purposes of this application, "wear-resistant" means that the wear-resistant element 19 is significantly less susceptible to wear than the friction element 18. The wear-resistant element 19 exhibits significantly higher strength and dimensional stability compared to the friction element 18.

[0021] The friction elements 18 and the wear-resistant elements 19 each comprise a radially outer contact surface 20 for force-fit interaction with the track 5 and a guide leg 12 angled relative to the contact surface 20. The function of the guide leg 12 is particularly well understood by means of Figure 2, which shows guide blocks 21 centrally on the inner side 22 of the track 5 on the wheel side. These guide blocks 21 serve to protect the track 5 from slipping laterally off the main wheels 3, 4. For this purpose, the guide blocks 21 are guided between the rims 16 of the respective main wheels 3, 4, with the opposing guide arms 12 of the transmission units 8 each providing lateral stop surfaces for the guide blocks 21. The friction elements 18 and the wear-resistant elements 19 of a rim 16 each extend in the axial direction of the drive wheel 11 along the entire width of the respective rim 16, resulting in a particularly effective contact surface 20 for power transmission between the track 5 and the drive wheel 11.

[0022] In the Figure 3In the illustrated embodiment, the friction elements 18 and wear-resistant elements 19 are arranged alternately in the circumferential direction of the drive wheel 11. Thus, in the circumferential direction of the drive wheel 11, each friction element 18 is followed by a wear-resistant element 19 arranged adjacent to it. In an alternative embodiment, in the circumferential direction of the drive wheel 11, each pair of adjacent friction elements 18 can be followed by a wear-resistant element 19.

[0023] Here, and preferably, the wear-resistant elements 19 comprise a profile formed on their contact surface 20. This is in the Figure 3 In the embodiment shown, the groove 23 is designed as a groove extending in the circumferential direction of the drive wheel 11. Alternatively, several grooves 23 can also be arranged on the contact surface 20 of the wear-resistant element 19. Reference symbol list:

[0024] 1 Track drive 2 Working machine 3 Main wheels 4 Main wheels 5 Track belt 6 Guide section 7 Ground 8 Transmission unit 9 Pivot axle 10 Pivot axle 11 Drive wheel 12 Guide leg 13 Auxiliary wheel 14 Rim segment 15 Ground section 16 Rim 17 Fastening element 18 Friction element 19 Wear-resistant element 20 Contact surface 21 Guide blocks 22 Inside 23 Groove

Claims

1. Crawler track (1) of an agricultural working machine (2) with a drive wheel (11) for driving an elastic crawler belt (5) of the crawler track (1), wherein friction elements (18) for force-locking interaction with the crawler belt (5) are arranged, in particular releasably, radially on the outside of the drive wheel (11), wherein at least one wear-resistant element (19) is arranged radially on the outside of the drive wheel (11) adjacent to at least one friction element (18), the at least one wear-resistant element (19) having a greater strength than the friction elements (18), characterized in that the drive wheel (11) comprises two rims (16) arranged side by side in the axial direction, the rims (16) each comprising friction elements (18) and at least one wear-resistant element (19), the friction elements (18) and the at least one wear-resistant element (19) of a rim (16) extending in the axial direction over the entire width of the respective rim (16).

2. Crawler track (1) according to Claim 1, characterized in that the at least one wear-resistant element (19) is composed of metal, in particular aluminium.

3. Crawler track (1) according to Claim 1 or 2, characterized in that the friction elements (18) are composed of elastomer, in particular rubber.

4. Crawler track (1) according to any one of Claims 1 to 3, characterized in that the drive wheel (11) comprises a plurality of friction elements (18) and wear-resistant elements (19) which are arranged alternately in the circumferential direction of the drive wheel (11), wherein, preferably, a wear-resistant element (19) is in each case arranged next to two adjacent friction elements (18), and, more preferably, the friction elements (18) and wear-resistant elements (19) are arranged alternately to each other such that a wear-resistant element (19) follows each friction element (18) in the circumferential direction of the drive wheel (11).

5. Crawler track (1) according to any one of Claims 1 to 4, characterized in that only the drive wheel (11) of the crawler track (1) comprises wear-resistant elements for interaction with the crawler belt (5).

6. Crawler track (1) according to any one of Claims 1 to 5, characterized in that the wear-resistant elements (19) on their contact surface (20), which interacts with the crawler belt (5), comprise a profiling, in particular one groove or a plurality of grooves (23) .