Qualidisc: Kverneland's new independent-disc harrow that aims to make people forget the DSA

Following the DSA, launched a few years ago and plagued by reliability problems, Kverneland is releasing a new independent-disc harrow: the Qualidisc.
It features concave notched discs of 565 mm in diameter mounted on rubber suspension. The range comprises 3 fixed-frame models from 3 to 4 m (Qualidisc 3000, 3500 and 4000) and 3 folding-frame models from 4 to 6 m (4000F, 5000F and 6000F).

The Qualidisc harrow uses the frame of the Kverneland cultivators. With its reinforced hitch head and its 100×100×8 mm frame, the Qualidisc independent-disc harrows can, according to Kverneland, support the heaviest rollers in the range.

A maintenance-free disc bearing

Each arm is fitted with a maintenance-free bearing that the brand describes as ?oversized? (with a shaft of 35 mm in diameter), made up of 2 rows of angular contact ball bearings. This bearing is said to be able to withstand the highest axial and radial loads.

Sealing on the arm side is provided by a labyrinth seal with 5 lips and by the seal that protects the bearing. On the opposite side, the disc presses against an O-ring to prevent dust from getting in.

According to Kverneland, ?the quality of the bearing and of the components used makes it possible to guarantee the machine for 2 years?.

The bearing is fixed to the arm by a nut, itself secured by an anti-loosening washer. The nut is protected from soil spray because it is set into the housing in the arm.

The choice of a 565 mm disc allowing work down to 15 cm (to be tested in the field!)

?To ensure cutting quality even at shallow depth, the Kverneland Qualidisc independent-disc harrow is equipped with large-diameter discs (565 mm)?, the brand states.

This diameter would make it possible to work even in the presence of large amounts of plant debris, for example with cover crops that must be destroyed before the next crop is established.

The notches around the edge of the disc are said to improve penetration and make it easier for the disc to turn in the presence of residues.

A constant cutting angle because the disc is concave

Whatever the diameter of the disc (due to wear), its cutting angle would always remain constant thanks to its concave shape. The 6 mm-thick disc undergoes a heat treatment that is said to give it very high hardness without impairing its ability to withstand impacts.

Its service life is extended and maintenance costs are reduced.

At the rear: a harrow and a choice of roller

The comb harrow, located after the second row of discs, just in front of the roller, is designed to cut the flow of soil but also to level it according to the selected aggressiveness setting.

Depending on the type of soil encountered, the consolidation expected, the soil/straw mix, the desired surface finish and the available lifting capacity, Kverneland offers a range of rollers:

- the ø550 mm cage roller

- the ø500 mm spiral roller

- the ø400 mm double cage roller

- the ø585 mm Flexline roller: a heavy furrowing roller, said to consolidate effectively in light to medium soils.

- the ø560 mm Actiring roller: an active roller with adjustable-pressure pads, said to ensure a good soil/straw mix and firm consolidation.

- the ø560 mm Actipack roller: heavier, it breaks up clods and would reconsolidate very firmly. ?It doesn't stop even in heavy, sticky conditions?, says Kverneland.