Ever more complex sequences of movements in indus - trial applications demand twistable and/or three-dimensional flexible cables with a long service life similar to the classic chainflex® cables for use in linear e-chain systems®.
Wires, stranded, shields and sheathing materials must compensate both major changes in bending load and changes in diameter due to torsional movements. For this purpose, different "soft" structural elements e.g. rayon fibres, PTFE elements or filling elements that absorb torsion forces are used in chainflex® ROBOT cables.
Special demands are made on the braided shielding in torsion cables. Torsion-optimised shield structures are chosen that can carry out the necessary compensatory movements thanks to special PTFE gliding films.
With twistable bus cables in particular, the transmission characteristics such as attenuation, cable capacity and signal quality must remain within very tight tolerance ranges over the whole service life. This is achieved through the use of particularly torsionoptimised insulating materials and mechanical attenuation elements with matching capacity values.
The highly abrasion-resistant, halogen-free and flameresistant PUR sheathing mixture in motor, hybrid/control cables and bus cables protects the torsion-optimised stranded elements from possible damage. The highly abrasion-resistant, halogen-free TPE-sheath mixture matches the special requirements of the twistable FOC and individual wires, and also protects the stranded elements.
Unlike cables for linear e-chain systems®, the "mechanical stress" for these cables is in the combination of bending, torsion and centrifugal forces that cannot usually be determined by design in advance or during use by means of measurement. For this reason, and unlike the situation with linear e-chain® applications, a clear "yes/no" statement cannot be made about the possibility of using a certain cable in torsion applications.
To enable evaluation to take place nevertheless, based on sensible and comparable test results, the igus® "torsion test standard" was developed.
According to this standard, all chainflex® ROBOT cables of a triflex® R energy chain are twisted with a fixed-point distance of one metre and a torsion of +/- 180° at least 3 million times.
In addition, a test is carried out on a test bench with a chain length of approx. 2500 mm with 270° torsion with an extreme load through centrifugal forces and heavy blows such as those that can occur with an industrial robot.
All the non-shielded, gusset-filled extruded standard chainflex® control cables of the series CF5, CF77.UL.D and CF 9 correspond to the above-mentioned igus® standard and have been approved for use in torsion applications with ±90° on 1 m cable length.
The following twistable CF ROBOT cable types are currently available:
Hybrid / control cables
Power / servo cable
Fiber optic cables