Roller bearings
Franke Wire Roller Bearings in Stage Technology – Rigoletto's Hand
The set design for the Bregenz Festival centered on an unusual challenge: Rigoletto’s right hand — eight meters high and weighing about 8.5 metric tons — had to be made rotatable.
In the end, the solution lay in two Franke rotary joints, each with a diameter of 600 millimeters, which serve as the hand’s central pivot axis.
The hand itself is hydraulically actuated and guided by eight joints, enabling a precise, reproducible pivoting motion. The goal was a swiveling, heavy-duty mounting that would function reliably even under live operating conditions. Two identical rotary joints were selected to ensure even load and motion distribution as well as redundant protection. The design thus relies on robust, low-vibration motion that can be reproduced even under varying loads and environmental conditions.
The requirements for the rotary joint were clearly defined:
- A generous center clearance to route cable ducts downward was just as much a priority as
- sealing on both sides against rain and seawater,
- a high degree of radial load-bearing capacity, and, last but not least,
- a short delivery time.
To meet these criteria, wire roller bearings from Franke were used. The center clearance of the assemblies allows the cables to run freely downward, thereby avoiding cable deflections and changes in space in the joint area.
Sealing is provided by a combination of a labyrinth seal and a lip seal, which reliably protects the raceways even under harsh environmental conditions. The robust design of the wire roller bearings ensures that the arm maintains stable, smooth motion even under heavy loads and frequent swivel cycles.
Why Wire Roller Bearings?
In a wire roller bearing, the rolling elements do not roll on solid housing rings, but rather on race wires made of high-strength steel. The delicate wires bear the load and allow for freedom in choosing the material and design of the surrounding structure.
Wire roller bearings offer a high degree of integration into existing assemblies, which reduces installation space and weight and shortens assembly time. This facilitates their implementation in complex stage structures, where weight savings and spatial constraints are often critical. At the same time, the modular design of wire roller bearings opens up new design possibilities and creates room for customization and innovation.
The modular nature of the construction method allows for the targeted use of environmentally friendly materials and the subsequent recyclability of components. This makes it possible to incorporate materials such as recycled aluminum, advanced plastics, or high-performance polymer materials into subsequent designs. In addition, modern manufacturing processes such as additive manufacturing enable new approaches to assemblies that are not only lighter but also more resource-efficient.
Conclusion
The use of two Franke rotary joints with a diameter of 600 mm enables a combination of generous center clearance, reliable sealing, high radial load capacity, and a compact design in stage technology. The modular, sustainable design makes it possible to implement robust, low-maintenance solutions—without compromising on performance.
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73431 Aalen
GERMANY
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