First two-seated solar aircraft

• What was needed: igubal® spherical plain bearings
• Requirements: light and high bearing between the different assemblies of the aircraft
• Industry: Aviation industry
• Success for the customer: Replacement of metal bearings with heavy-duty high-performance bearings from the plastics sector. The igubal®-bearing brings a high weight saving and enables better load distribution.

Solar flight pioneer Eric Raymond is setting new standards in several areas with his company Solar Flight as part of a project launched in 2011, the SUNSEEKER DUO. The world's first solar-powered two-seater was built in collaboration with several well-known partners from the industry. The development of this completely new concept often required unconventional and tricky solutions.
For each individual component, the aim was to achieve outstanding technical specifications for optimum performance. The technically highly stressed connecting links between the individual assemblies are particularly interesting. In most cases, only high-performance metals could be considered as materials for the bearings. This was also the case for the design of the wing suspension, for which an easy-to-assemble connecting element had to be found. In addition, the wing was to be rotatably mounted in order to be able to adjust the angle of attack of the airflow in flight. A bearing solution had to be found at various points, such as on the flaps or on the rudder, which would not only be able to withstand high loads without any problems. As every gram was important, a particularly lightweight product also had to be found.

Eric Raymond is breaking new ground with the SUNSEEKER DUO and is increasingly focussing on solid plastic plain bearings. With a similar load capacity, plastic plain bearings offer several advantages, as can be seen in the example of the sash suspension:
The spherical plain bearings offer optimum specifications for the sash suspension. By using plastic instead of metal, it is not only possible to save weight here. Plastic spherical plain bearings are designed to be larger to ensure sufficient load-bearing capacity, which simplifies integration into the component and ensures better load distribution. In the case of the wing suspension, two igubal® spherical plain bearings of type KGLM-30-LC are used in the SUNSEEKER DUO for the first time in the history of aircraft construction. These are completely laminated into the wing spar and connected to the fuselage via a carbon bolt.
In other places, too, metal bearings are replaced by plastic for the first time thanks to an unbiased design. Our spherical plain bearings are relied upon for the suspension of the tailplane with the same advantages.
igus® PEP bearings have proven to be the optimum connecting element for attaching the flaps to the wing. Here, too, the advantages of a much simpler plastic-plastic integration into the assembly are evident. In addition, the load-bearing shaft could be made of carbon fibre, which brings further weight savings.