Torsion vs Bending: Why Robot Cables Need Special Design
Industry analysis highlights that torsion is fundamentally different from bending in cable engineering . Bending involves stress distribution across the cable cross-section (tension on outer side, compression on inner), while torsion creates shear stress around the axis.
Key Distinction:
Aspect | Bending (Drag Chain Cables) | Torsion (Robot Cables) |
|---|---|---|
Motion Form | Back-and-forth in one plane | Rotation around cable axis |
Stress Nature | Tension/compression on cross-section | Shear around axis + spiral tension |
Key Structure | Short lay length, strand exchange | Spiral cabling, central anti-torque core |
Failure Mode | Outer conductor fatigue | Conductor break from spiral tension, jacket wrinkling |
Implication: A standard drag chain cable designed for bending cannot be used for torsional applications. Robot cables must be specifically designed with spiral cabling arrangements, central anti-torque elements, and slip layers that allow conductors to "breathe" during twisting
