Maximum freedom of movement for industrial robots

Compact articulated robots for industrial applications continue to present design engineers with challenges regarding energy supply systems. This is because there are currently few suitable solutions on the market to accommodate the rapid rotational movements along the first axis and the confined spatial conditions involved. Igus is now closing this gap with a new self-supporting energy chain from the *twisterchain* series. At the same time, it solves a second problem: energy guidance along the fifth axis of palletizing robots. In this area, too, many design engineers have until now been experimenting with custom-made solutions.

Compact industrial robots – such as the KR Agilus from Kuka or the Fanuc LR Mate – can be found everywhere in the industrial sector. They perform screwing, gluing, and assembly tasks, as well as "pick-and-place" operations. Yet, established as these robots may be, one problem has persisted throughout their history. "For cable routing at the base of these small robots – which rotate a full 360 degrees – there are currently no suitable rotary modules on the market capable of following the movement," says Matthias Meyer, Head of the *triflex* e-chains and Robotics division at igus.

The reason for this is often the power supply connector plate located on the back of the robot, which obstructs the path of rotary modules. "Consequently, many design engineers still resort to stopgap measures – such as dangling hoses that drag across the floor and, as a result, wear out very quickly." To resolve this issue, igus is now launching a self-supporting *twisterchain* energy guidance system. The rotary module arcs around the base of the robot – resting either directly on the floor or on a raised pedestal.

The fixed point is anchored to the mounting surface, while the moving end is attached slightly higher up, to the robot's first axis. As the robot rotates, the energy chain lifts upward in stages, shifting into a new plane. "This allows us, for the first time, to achieve a full 360-degree rotation around the robot's base without colliding with the connector housing," says Matthias Meyer. Improvised solutions are no longer necessary, resulting in a significant increase in the operational reliability of compact industrial robots.

Secure guidance for the fifth axis of palletizing robots

With the new self-supporting twisterchain, igus simultaneously addresses a second issue: energy supply guidance on the fifth axis of palletizing robots. In many cases, these robots route cables through the robot arm – but only as far as the fourth axis. "Until now, suitable solutions for the rotational movement at the fifth axis have been lacking. Designers often resort to using corrugated hoses, which move uncontrollably and can collide with the tool," says Matthias Meyer. The self-supporting twisterchain can be deployed here as well to ensure greater safety. Its specially developed design enables energy and data cables on the fifth axis to follow the 360-degree rotations of the tool. Thanks to controlled and defined movement across two planes, collisions between the cables and the robot arm or tool are effectively eliminated. "This system thus offers maximum freedom of movement for applications involving extended rotation angles, ensuring permanently reliable energy supply guidance – even with highly dynamic motion profiles," notes Matthias Meyer.

Rapid installation and simple retrofitting

The new twisterchain variant can be installed quickly. "Since the solution is self-supporting, we require only two mounting points on the robot. Expensive guide troughs and complicated alignment procedures are rendered unnecessary," emphasizes Matthias Meyer. Furthermore, thanks to a flexible interior layout featuring removable dividers, the energy chains can be adapted to accommodate various cable configurations. Another advantage: the energy chains can be opened from the inner radius, allowing users to insert cables from the outside. Matthias Meyer explains: "This represents a major advantage over hoses, where cables must be threaded through. In those cases, varying connector sizes frequently act as a limiting factor." To ensure precise adaptation to any application, the system features adjustable preload. This can be precisely tuned to match the cable weight and required angle of rotation – a decisive advantage for the fine-tuning of robots and machinery that demand the highest levels of repeatability and stability.