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

Profile

• What was needed: ready-to-install chainflex cable sets for energy and signal transmission
• Requirements: UV and moisture-resistant, torsional resistance, temperature stable, notch-resistant & low wear
• Industry: agriculture, special harvesters
• Success for the customer: time and cost savings compared to internal assembly as well as long service life and flexible handling of the cables used

The harvesting machines from ZEMA allow a semi-automatic harvesting and processing operation right in the field. (Source: Josef Zeyer GmbH)

Problem

Josef Zeyer GmbH builds harvesting machines for vegetables and lettuce, which are always designed and manufactured according to customer specifications. The mobile machines reach an impressive size of up to 10 x 9 metres (when extended), so that the just-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 whilst still in the field. It then travels via a conveyor belt to the inside of the harvesting vehicle, where it can then be further processed.
The machine travels in the field at around 40 metres per hour, either automatically or sensor-controlled in 'platooning' mode behind a tractor. However, the driver must still be able to readjust, for which - as well as for turning at the end of the field - he uses a wired remote control. In addition to the drives and steering, which are controlled electronically via CAN bus, the level control, i.e. the distance between the harvester and the ground, is also controlled via remote control.
It is true that the flexible cable connecting the remote control and the 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 to various torsions and very different temperatures. And, as they are often pulled along the ground, the amount of wear increases.

Solution

Since conventional cables do not meet the ZEMA requirements for service life, the company basically uses chainflex cables from igus for remote controls. The chainflex cables are designed quite differently from those for static applications: the principle of cores wound in bundles ensures that the tensile and compressive forces acting on the individual cores during movement are balanced. This creates an essential prerequisite for a long service life in moving applications - without broken cores and corkscrews. The high-quality materials and the special extrusion process prevent further causes of failure, for example jacket abrasion and insulation damage.
Twistable chainflex cables of the CFROBOT9 series are used in the ZEMA machines. The cables achieve a long service life in the field and also facilitate the handling of the remote control because they are more flexible and therefore more mobile.
ZEMA obtains the cable sets as fully harnessed energy supply systems (readycable). This has the advantage that the customer saves a lot of time and does not have to keep plug-in connectors or other accessories ready. And despite the commitment to one standard, Josef Zeyer GmbH remains flexible because the harnessed cables can be ordered in different lengths.

The machines move at around 40 metres per hour and in the field can be readjusted or operated by remote control.

The chainflex CFROBOT cables were specially developed for flexible applications. They therefore achieve a significantly longer service life - not only in harvesting technology.