New LEXION takes straw-walker combines to higher level

As part of the natural evolution of the CLAAS LEXION range, the introduction of the new second generation LEXION 6000 and 5000 range of straw-walkers combine harvesters see’s not only a considerable expansion in models available, but also the introduction of a host of new features all designed to provide a further increase in output and efficiency.

Redesigned from the ground up, central to the new LEXION 6000/5000 range of combines is the completely new APS SYNFLOW WALKER threshing system, which sets a new standard for the threshing and separation performance from straw-walker combines. A total of seven new models are available in the range, comprising four 6-walker LEXION 6000 versions and three 5-walker LEXION 5000 models. This compares to five models in the previous LEXION 600 range, of which three were six-walker and two were five-walker.

Topping the range is the new LEXION 6900 which, with a power output of 507hp and maximum grain tank capacity of 13,500 litres, further extends the overlap between LEXION straw-walker and HYBRID models.

In addition to the new SYNFLOW WALKER threshing system, the LEXION 6000/5000 also features the well-proven JETSTREAM cleaning system on all models. Tank capacities and unloading volumes have also been increased, while new engines provide greater power and the introduction of DYNAMIC POWER. In the cab, the operator benefits from a state-of-the-art workplace with the latest touchscreen CEBIS terminal and the option of advanced automated operator assistance systems.

The APS threshing system has been key to the high performance of the LEXION since its introduction 25 years ago. The development of the new APS SYNFLOW WALKER system takes the threshing and separation performance from the LEXION 6000/5000 to a new level. This is achieved by bringing together the accelerated crop flow provided by the APS system but adding to this an additional separator drum after the threshing drum.

Central to the all-new threshing system is the massive 755mm diameter threshing drum, fitted with 10 rasp bars, which is 26% larger than the 600mm drum on the LEXION 600 range. Behind this is the new 600mm-diameter separator drum that provides additional gentle separation of grain from the straw.

The greater diameter of the main threshing and separating drums has the benefit that the concave wrap angle is shallower at 132° and 116° respectively. As a result, straw flow through the APS SYNFLOW WALKER system is flatter and gentler, resulting in improved straw quality, but load on the threshing system is reduced, so saving power and fuel.

The shallower angles also mean that the main concave area has been considerably increased. At 1.30m2, the 1,420mm-wide unit fitted to the 5-walker LEXION 5000 now has a larger concave area than the current largest LEXION 670 six-walker model (1.22m2) while in the 1,700mm-wide unit fitted to LEXION 6000 models it’s a massive 1.55m2.

Due to the wider diameter and higher centrifugal speed of the rasp bars, to maintain velocity this means that drum speed has been reduced, and is now infinitely variable using CEBIS from 330-930rpm. Drum speed is also synchronised across all four drums.

For optimum performance across all crop types and conditions, the main concaves are easily infinitely adjusted hydraulically using CEBIS. This provides both parallel and synchronised adjustment of the pre-concave, threshing concave and separator concaves, so ensuring an even flow of material through the threshing system. Where it’s necessary to change the concaves, for instance when harvesting beans, this is quickly and easily done and 40% of the main concave can be pulled out sideways.

Where greater threshing intensity is needed, for instance in difficult to thresh crops or for deawning barley, the APS SYNFLOW WALKER system incorporates an additional pivoting concave bar located between the pre-separation concave and the main concave, again engaged hydraulically using CEBIS.

A new feature on LEXION 6000/5000 straw-walker combines is the JET STREAM cleaning system, which was previously only found on LEXION HYBRID models. Depending on model, the six or eight turbine fans venting through a dual straw-walker step and a long airflow equalisation channel provide intensive pre-cleaning of the grain. The sieves and fan are adjusted electrically from the cab.