As industrial robotic applications become more and more demanding, we’re finding an increased need for flexible cables that can handle extremely complex movements and still deliver a long service life. When specifying cables for these types of applications, there are some important features to look for.
In order for a cable to withstand repeated torsional movement, it’s necessary for the cable to have a special design. It’s important that the conductors, shield construction and jacket materials of the cable compensate for major changes in bending load and diameter. To accomplish this, igus® uses "soft" structural elements—rayon fibers, PTFE elements or filling elements—that absorb torsional forces. When data transmission is essential, we use specially engineered insulation systems to ensure performance remains within a specified range over the cable’s service life.
In contrast to conventional braided copper shields, a torsion-resistant, tin-plated copper shield sheath is used in igus®’ chainflex® CF Robot cables. The forces affected on the cable by any torsional movement are largely absorbed by sliding and buffer elements between the sheath, shield and insulation. Using a highly abrasion-resistant, halogen-free and flame-resistant PUR or TPE sheathing mixture prevents early failure of the shield and also protects the cable components from potential damage.
It’s also important to keep in mind that robot cables, unlike traditional continuous-flex types, can withstand various "mechanical stresses", including bending, torsion, centrifugal forces or a combination of all three. However, it’s nearly impossible to determine in advance what these cables can handle, even when taking into account their design or performance during use. So, to better evaluate these cables, igus® developed a "torsion test standard”. According to this standard, all CF Robot cables have been tested in the igus® test laboratory through more than three million torsional movements to +/- 270 degrees without failure.
Choosing cables for a robotic application can be challenging so paying close attention to a cable’s construction and working with a company that performs in-house testing can be key.
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