Flexible energy chain for innovative cable robots in automated high-bay warehouses

What was needed: e-spool energy chain

Requirements: With the fast horizontal, vertical and diagonal movements, supplying the various cables poses a major problem that cannot be solved with conventional cable systems

Industries: Material handling, warehouse operating equipment

Success for the customer: The cable robot with igus energy chain and e-spool demonstrates a well-thought-out solution that allows for effective warehouse management while counteracting the disadvantage of increasingly heavy storage and retrieval units

Tall shelving systems are ideal to store goods effectively in small spaces. They also permit the use of fully automated storage and retrieval units. However, the conventional design has one disadvantage: the higher the shelves become, the heavier the storage and retrieval machines are due to the rigidity requirements. While the containers or goods being moved are often very light, the storage and retrieval machines can weigh up to 2t.

The winner of the 2014 igus golden vector award is a cable robot that offers a solution to the weight problem. The robot, which is used in automated high-bay warehouses, was developed by the University of Duisburg-Essen. The system is based on a transport platform with a gripper that moves around using eight parallel wire ropes. The major challenge that inevitably comes with this idea is that the fast movements in three-dimensional space open up questions regarding the supply of energy, which only a sophisticated system can solve.

The biggest problem with the concept for this storage and retrieval unit was the fast movements that take place in three dimensions. To prevent the abrupt horizontal, vertical and diagonal movements from creating tangled cables, all supply cables are guided in an igus e-chain, which rolls up and down on an e-spool.

As an alternative to the cable drum, the e-spool can be used as it is safe and gentle on energy chains and cables. It is used in particular when many different cables need to be guided in a confined space. A roller guides a standard energy chain and an integrated retaining spring ensures that the energy supply cable is always exactly the right length and tension. In the starting position, the energy chain is completely rolled up to save space. The twisterband connects the roller to the shaft end block, which serves as an interface to the permanently installed cable.