Roller bearings function as a mooring-system for the self-alignment of floating wind turbines

Ming Yang is moving forward with the development of the Nezzy² platform. This is a 16.6 MW twin floating offshore wind platform, consisting of two 8.3 MW wind turbines. Their V-shaped downwind rotors have a diameter of 180 metres each.

The rotors are mounted on a floating, self-aligning structure, that consists of an anchor buoy, a mooring bearing, and a steel structure as a floating foundation. The structures are anchored to the seabed by steel cables. An underwater cable transmits the generated electricity to the coast.

To ensure the self-alignment of these turbines, the Liebherr slewing bearings function as a mooring system. For this purpose, a bearing with a diameter of four metres is installed as a connecting element between the anchor buoy and the float below the sea surface. Because the slewing bearing has to withstand high pressure and corrosive environmental conditions, some components are made of stainless steel or welded on with stainless steel. In addition, the bearing has two sensors that can detect the event of water ingress at two measuring points. One is located in the first lower chamber, and the second is located in the second upper chamber of the floating turbine. In case of maintenance or repair, the float with the turbines can be separated from the anchor buoy and towed to a harbour.