Flexible and torsionally rigid energy and signal cable technology in harvesting technology

Josef Zeyer GmbH builds harvesting machines for vegetables and lettuce, which are always customised and manufactured. The mobile machines reach an impressive size of up to 10 x 9 metres (when extended) so that the harvested produce can be processed as quickly and freshly as possible. The harvest is washed, portioned, packed and palletised manually by staff from a bridge while still in the field. It is then transported via a conveyor belt to the inside of the harvesting vehicle, where it can be processed further.
The machine travels at around 40 metres per hour in the field, either automatically or sensor-controlled in 'platooning' mode behind a tractor unit. However, the driver must still be able to readjust, for which he uses a wired remote control - as well as for turning at the end of the field. In addition to the drives and steering, which are controlled electronically via CAN bus, the levelling system, i.e. the distance between the harvester and the ground, is also controlled via the remote control.
The flexible cable that connects the remote control and vehicle does not have to perform a high number of cycles or extreme movements. Nevertheless, the stresses and strains should not be underestimated. The cables are exposed to UV rays and moisture, but in particular also to various torsions and very different temperatures. And they are often dragged across the floor, which increases wear.

As conventional cables do not fulfil the ZEMA service life requirements, the company generally uses chainflex® cables from igus® for its remote controls. chainflex® cables are constructed very differently to those for static applications: The principle of bundle stranding ensures that the tensile and compressive forces acting on the individual cores during movement are equalised. This creates an essential prerequisite for a long service life in moving applications - without core rupture and corkscrew. The high-quality materials and the special extrusion process prevent other causes of failure such as sheath abrasion and insulation damage.
Twistable chainflex® cables from the CFROBOT9 series are used in the ZEMA machines. The cables achieve a high service life in the field and also facilitate the handling of the remote control because they are more flexible and therefore more manoeuvrable.
ZEMA obtains the cable sets as ready-made energy supply systems(readycable®). This has the advantage that the customer saves a lot of time and does not have to keep any connectors or other accessories on hand. And despite being committed to a standard, Josef Zeyer GmbH remains flexible because the pre-assembled cables can be ordered in different lengths.