First two-seated solar aircraft

Profile

• What was needed: igubal spherical bearings
• Requirements: Easy and high bearing arrangement between the different assembly groups of the aircraft
• Industry: Aviation industry
• Success for the customer: Replacement of metal bearings with heavy-duty high-performance bearings made of plastic. The igubal bearings bring a high weight saving and enable a better load distribution.

Problem

Solar flight pioneer Eric Raymond is setting new standards in several sectors 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 in the industry. In the development of this completely new concept, unconventional and tricky approaches are often needed.
For each individual component, the aim was to achieve outstanding technical specifications for optimum performance. The technically highly stressed joining links between the individual assemblies are of special interest. In most cases, only high-performance metals were considered as materials for the bearings. This was also the case with the design of the wing attachment, for which an  easy-to-assemble joining link had to be found. Furthermore, the wing should be pivoted in order to be able to adjust the airflow angle in flight. A bearing solution had to be found at various points, such as the flaps or the rudder, that could do more than just easily cope with heavy loads. Since every gram mattered, a particularly lightweight product also had to be found.

Solution

Eric Raymond is breaking new ground with the SUNSEEKER DUO and is increasingly using solid plastic plain bearings. With similar load capacity, plastic plain bearings bring several advantages, as can be shown with the example of the wing attachment:
The spherical plain bearings offer ideal specifications for the wing attachment mounting. By using plastic instead of metal, it is not only weight that can be saved here. Plastic spherical plain bearings are designed larger for sufficient load capacity, which simplifies integration into the component and ensures better load distribution. In the case of the wing attachment, two igubal spherical bearings of the type KGLM-30-LC are used in the SUNSEEKER DUO for the first time in the history of aircraft construction. It is completely laminated into the wing spar and connected to the fuselage via a carbon bolt.
In other places, too, an even-handed design replaces metal bearings with plastic for the first time. Thus, with the same advantages, our spherical bearings are also relied on for the suspension of the horizontal stabiliser.
When attaching the flaps to the wing, igus PEP bearings proved to be the optimal joining link. Here, too, the advantages of a much simpler plastic-plastic integration into the assembly become apparent. In addition, it was possible to make the load-bearing shaft out of carbon, which resulted in further weight savings.

Plastic bearing technology is used in a wide variety of places on the solar aircraft.

The wing spar is prepared for the installation of the bearings.