User friendly new generation potato harvesters
The latest generation of the GRIMME’s EVO 280 potato harvester is equipped with an integral hydraulic drive-system, alongside updates for ease of maintenance and user-friendliness.
Industry estimates suggest that areas planted have increased from about 10,000ha in 2010 to a best estimate of around 45,000ha in 2015.
The crop appears to go from strength to strength, no doubt helped by the need for a seedbed not that much finer than one for maize, a resistance to diseases associated with brassicas and high dry matter yields per hectare.
Obviously as the areas planted get larger, the machines needed to harvest them get bigger too. One such machine, fresh off the wharf, was the Grimme Rexor 620 which packs a lot of superlatives into its spec sheet. Length 13.3m, height 6.4m, weight empty 26.5 tonnes, loaded 48.5 tonnes, and a fuel tank of 1300L.
Probably better known for its equipment in the world of potatoes, Grimme has nevertheless had an involvement with beet harvesters since 2003.
The Rexor 620 is a twin axle bunker style machine with a six row harvesting system and a bunker capacity of around 22 tonnes. Given that its fully loaded weight is approaching 50 tonnes, it has a unique dog-leg wheel layout that during harvesting enables the wheels follow separate tracks across the full width of the machine to minimise soil damage; tight turns are taken care of via an articulated joint in the centre of the machine.
Power is generated by a straight Mercedes engine developing 490hp in an engine rev range of 1150-1600 rpm to produce efficient fuel consumption figures.
At the heart of the machine, the harvesting elements, sees a topping unit up front, clearing 6 rows with spacing 45-50cm, with in-line delivery. Following on the scalping unit uses a parallel guidance system to remove the crowns of the beet with minimum wastage. Next stage is the Oppel lifting wheels, working in pairs and individually hydraulically driven which ‘pluck’ the roots from the ground, rather than rely on a more typical digging share. This lifting wheel design ensures less stones and dirt being lifted, as the crop is presented to the cleaning segment of the machine.
Traditionally the transition from harvesting to cleaning on self- propelled harvesters can be a bottleneck, and this is addressed on the Rexor by a 90cm wide web that is hydraulically driven, and thereby offers about 20cm more clearance between the table and the chassis because there are no driveshafts.
Second stage cleaning is via three rotary turbines, which have steplessly variable speed and hydraulic guide bar adjustment to ensure a clean sample is delivered to the bunker in all types of conditions.
From the cleaning turbines crop is delivered to the 33m3 (22 tonne) capacity bunker by a ring elevator, before being unloaded by a combination of moving floor and 1800mm wide unloading elevator.
As one would expect of a machine of this size, tyres are extremely important, and the unit is shod with 1050-50 R32 rears and 800-70 R38 fronts, the latter used to ensure maximum clearance in the harvesting section in difficult conditions. Hydraulics are taken care of by a closed circuit load sensing system with split circuits to ensure a plentiful supply to all areas at all times.
The driver is cosseted in a cabin provided by Claas, with auto-steering, touch screen control and three cameras to ensure the machine performs at its optimum for long harvest days.
As for the age-old question “what’ll she do mister”… depending on conditions and the ability of the support crew to get the crop away from the harvester, 1-2ha/hour. So taking into account a wet yield of around 120 tonnes/ha (22-25 tonnes DM) you could end up with a large pile at the end of the day.
