harvesting also on slopes

Keeping productivity without compromising the quality of the harvest and ensuring a clean product is difficult, especially in operations on sloping terrain. Combining highly evolved manufacturing techniques and sensor and electronic systems have considerably helped achieving this objective. The top brand names producing combine harvesters rely on innovative and original solutions, often created by specialized supplier companies

A combine harvester is undoubtedly one of the most complicated among the machines now used in farming. Compared to the fixed-point harvesters built in the 1950s, traditional models with the standard straw walkers stayed much the same for a very long time. After this lengthy stall, axial and then hybrid combine harvesters began appearing in the 1980s, finally with the elimination of the straw walker seen as the bottleneck for raising productivity.   

Levelling

In all cases, including traditional machines, revisions and modifications have been applied recently, especially for cleaning grain which enables the machine to operate efficiently without any unwanted increase in losses and work on sloping land without compromising the stability of the machine and ensuring critical operation of screening devices and normal cleaning. In these conditions, referred to as medium slope widely used in Europe for cereal grains, transversal levelling can be used as well as self-levelling which also operates on the longitudinal plain which adds considerable costs to the combine. However, intermediate options have been available for some time, that is, models which activate levelling only of the internal components or those with similar solutions making it possible to perform efficient work on plots with slopes of a certain degree.

The technological solutions 

There are various mechanisms designed to avoid downhill clogging due to the weight of the product in sieve or straw walker areas and to maintain uniform feed of the product or facilitate the management of the overload portion.

The technical solutions now available often seem very differentiated they all meet the same requirement of automatically compensating an unbalanced flow of the product to avoid increased losses and/or compromising efficient cleaning.

John Deere S Series combines are equipped with ATA, Active Terrain Adjustment, which works exclusively off a fan whereas the AGCO Group has chosen for their brand names Fendt and Laverda differential air flows in the different work areas. To accentuate compensation the system differentiates correction according to the type of grain. The John Deere solution combines the regulation activities of opening the lower and upper sieves.

Class recently introduced an Auto Slope function, an automatic module with progressive fan speed which increases uphill and slows downhill according to the pre-set value for work on the level. Moreover, the Claas Tucano and Montana series are equipped with 3D and 4D: the 3D works efficiently on transverse slopes of up to 20% with a hydraulic cylinder for driving the sieve in the opposite direction on the slope to compensate the force of gravity which tends to accumulate the grain on the downhill side of the sieve. On the other hand, the 4D is adopted for the hybrid machine, that is, the conventional combine with beater and counter beater but with the straw walker replaces by a pair of dedicated rotors. In this case, the rotor grills become partially and gradually occluded: in practice, the most downhill operative is progressively reduced to reduce accumulation here.

The New Holland and Case IH models, though the brand names are different, are equipped with the OptiFan which automatically regulatesthe fan to compensate longitudinal slopes and is completed by the SmartSieve, another automatic system for compensation on transversal slopes. At work, the OptiFan increases the flow of air downhill and reduces it uphill whereas the SmartSieve beats the sieve at high frequency using a hydraulic cylinder for a uniform distribution of the grain inside the available surface. For the top-model combines there is a sieve with self-levelling in three directions thanks to hinges on the frame with a central mount which compensates on transversal slopes of up to 17%.

If the slopes are steep

When the terrain is no longer apparently level but features steep slopes, levelling at least partially, is clearly required inside the machine.

Though these machines may not fully provide the performance of totally self-levelling combines they work well enough on medium hilly terrain with operational costs, and return on investment, similar to conventional machines. The very active specialized SME sector is outstanding for ingenuity of the solutions developed. With the exception of Laverda and the brands in the AGCO Group, in this niche market these enterprises are now increasing the potential of their machines even up to the level of the multinational majors and turning to domestic suppliers. An example is New Holland which manufacturers machinery in Zedelgem in Belgium and Plock in Poland and for the TC and CX Series they turn to Zaffrani in Macerata, Italy for transforming the Hillside Series. Moreover, Zaffrani supplies Deutz-Fahr

with rear levelling for the Balance Series. Deutz-Fahr also used the Piacenza firm Comep for the 6060 Climber Series and Comep also supplies levelling components for the Claas Montana Series. Possanzini di Jesi, other than work for various European manufacturers, the company supplies John Deere with rear levelling for the HillMaster.