Maintenance platform for wind turbines

Profile

• What was needed: chainflex® cables; energy chains with Reverse Bend Radius; drylin® guide systems; iglidur® plain bearings; tribo-tape liners
• Requirements: the cables and energy chains had to be particularly flexible due to the mobile platform; furthermore, environmental conditions were harsh, including vibrations, UV loads and large temperature ranges
• Industry: renewable energy, wind turbines
• Success for the customer: control, signal and bus cables are provided entirely from the chainflex® product range; a newly developed, especially lightweight aramid cable allows for the platform's energy supply; an energy chain with Reverse Bend Radius (RBR) takes on the complex task of guiding the cables in the platform's rotary axis

The "mobile workshop" for the repair of wind turbine rotors is movable in all dimensions and protects service personnel from wind and weather.

Problem

The rotor blades of wind turbines, which have been laminated by hand, are subject to wear due to abrasion, bird strike and high mechanical stress. For these reasons, it is obligatory to maintain the rotors regularly. However, very often wind and weather make it impossible to access the rotor blades.
Therefore, the start-up company WP Systems GmbH offers the "terra" system, which can be adapted exactly to the shape of the rotor blade and increases the servicing time to around 200 days. Here, the staff works on a mobile maintenance platform.
The system operates with three tensioned cables from the housing, 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. In addition, the platform can be enlarged in the working position by extending so-called "balconies".
The service technician's workplace on the terra platform is completely enclosed and well-lit so that night work is also possible. Furthermore, there is a mobile work table and numerous sockets for tools. And since high humidity can affect the quality of repairs to the GRP rotors, the maintenance chamber can be heated using infrared.
Where electricity is available and data is processed, installed cables have to be very flexible due to the mobile platform. What's more, environmental conditions are harsh, including vibrations, UV loads and large temperature ranges.

Solution

Today, our cable solutions can be found in the application, more precisely in a cable trolley that is exclusively fitted with chainflex cable reels. From our chainflex® product range, control, signal and bus cables are used.
We have developed a special cable to supply the platform with energy from the trailer - a 32A/ 400V cable made of light aramid - where every kilogramme counts. This is important as the load capacity of the winches for passenger transport is limited. The lighter the platform, the more tools and material can be transported.
Some of the chainflex cables on the "terra" are guided in our energy chains. The largest chain is designed with a Reverse Bend Radius (RBR) and takes on the cable guiding in the platform's rotary axis, which is necessary to be able to reproduce the "twist" of the rotor. It is a special edition from the igus modular system.
The tarpaulins on the bow and stern modules are moved via drylin guide systems. Some extendible elements of the platform rest on tribo-tape liners , and various lead screw elements and axes are guided in sleeve bearings made of iglidur® high-performance polymers.
Finally, chainflex® cables are used in the "structrepair", the start-up's repair system for the glass fibre structures of the rotor blades. The service staff no longer have to do elaborate lamination and account for many hours of curing time. Instead, a pre-impregnated "sheet" is applied and attached to the rotor under vacuum. This takes about 30 minutes. Here, the chainflex cable connects the process unit with the vacuum-building silicone heating mat and guides both energy and sensor signals for temperature control.

The rotor blades of wind turbines, which have been laminated by hand, are subject to wear due to abrasion, bird strike and high mechanical stress.

Our energy chains guide the chainflex cables to the numerous moving components of the "terra" platform.

The tarpaulins for weather protection are opened and closed using drylin linear guides.

Our iglidur tribo-tape is a lightweight solution to reduce friction during linear movements.

Our plain bearings are installed on various axes. Lightweight, maintenance-free and lubrication-free operation and insensitivity to corrosion are major advantages here.