Maintenance platform for wind turbines

• What was needed: chainflex® cable; energy chain with reverse bend radius; drylin® guide system; iglidur® plain bearings; Tribo-Tape sliding foils
• Requirements: the cable and energy chain had to be particularly flexible due to the mobile platform; in addition, there are adverse environmental conditions such as vibrations, UV load and large temperature ranges
• Industry: Renewable energies, wind turbines
• Success for the customer: Control, signal and bus cables are provided entirely from the chainflex® programme; a newly developed, particularly lightweight cable made from Amramid enables the platform to be supplied with energy; an energy chain with reverse bend radius (reverse bend radius) takes over the complex cable routing in the rotary axis of the platform

The hand-laminated rotor blades of wind turbines are subject to wear, for example due to abrasion, bird strikes and high mechanical stress. For these reasons, regular maintenance of the rotors is mandatory. However, wind and weather often make it impossible to access the rotor blades.
This is why the start-up company WP Systems GmbH offers the "terra" system, which can be adapted precisely to the shape of the rotor blade and increases the service time to around 200 days. The personnel work on a mobile maintenance platform.
The system works with three cable guy ropes from the nacelle, which are controlled by winches, and a support on the tower. This makes the platform vertically mobile. It can be moved horizontally over a distance of up to 15 metres. And the maintenance chamber can even follow the rotation of the rotor blade from the base to the tip. The platform can also be enlarged in the working position by extending so-called "balconies".
The service technician's workstation on the terra platform is completely enclosed and optimally illuminated, so that night work is also possible. There is also a movable work table and numerous sockets for tools. And because high humidity can impair the quality of repairs to the glass-fibre reinforced plastic rotors, the maintenance chamber can be heated using infrared.
However, where power is available and data is processed, cables also have to be installed, which had to be particularly flexible due to the mobile platform. In addition, there are adverse environmental conditions such as vibrations, UV load and wide temperature ranges.

Today, our cable solutions can be found in the application, more precisely in a cable trolley that is equipped exclusively with chainflex® cable reels. Both control, signal and bus cables from our chainflex® programme are used.
For the power supply to the platform from the trailer, we have developed a special cable - a 32A/ 400V cable made of lightweight Amramid - where every kilogram counts. This is because the load capacity of the winches for passenger transport is limited. The lighter the platform, the more tools and materials can be carried.
Some of the chainflex® cables on the terra are guided in our energy chains. The largest chain is designed with a reverse bend radius and takes over the cable routing in the rotary axis of the platform, which is necessary to be able to reproduce the "twist" of the rotor. This is a special design from the igus® modular system.
The tarpaulins on the front and rear modules are moved via drylin® guide system. Some extendable elements of the platform rest on Tribo-Tape sliding foils and various spindle elements and axis are guided in cylindrical plain bearings made of iglidur® high-performance polymers.
Finally, chainflex® cables are also used in "structrepair", the start-up's repair system for the glass fibre structures of the rotor blades. Service personnel no longer have to carry out time-consuming laminating and allow for many hours of curing time. Instead, a pre-impregnated "sheet" is applied and bonded to the rotor under vacuum. This takes around 30 minutes. The chainflex®-cable connects the process unit with the vacuum-building silicone heating mat and carries both energy and sensor signals for temperature control.