Schaeffler Group Developed An Innovative, Single Bearing Solution For Rotor Head

Schaeffler Group Developed An Innovative, Single Bearing Solution For Rotor Head The Schaeffler Group has developed an innovative, single bearing solution for the rotor head on Multibrid's M5000 5MW offshore wind turbine. Wind turbine manufacturer Multibrid's new M5000 offshore wind turbine is the world's most compact, lightweight 5MW category system. Key to this is a large, single rolling bearing that directly supports the rotor hub. The Schaeffler Group has developed an innovative, single bearing solution for the rotor head on Multibrid's M5000 5MW offshore wind turbine. The double-row tapered roller bearing weighs around 7200kg and has an outside diameter of 3200mm, a bore diameter of 2620mm and a width of 485mm. Designed in accordance with German wind turbine developer Multibrid's novel drive train concept, the turbine solution features a rotor hub that is directly supported by Schaeffler's large rolling bearing in the machine housing. In order to minimise any detrimental effects of the rotor loads on the gearbox and generator, Schaeffler's customised double-row tapered roller bearing transfers these loads to the adjacent structure, bypassing the gearbox-generator unit. Thanks to the absence of a high speed gear stage, the tower head has a relatively low weight of around 300 tonnes, which enables the turbine to be pre-assembled on land so that the nacelle can be hoisted to the tower at sea with only one lift. The total weight of the tower head - including the rotor blades, which are attached to the hub at a height of 102m and measure 56.5m in length - is 310 tonnes, making it the lightest 5MW wind turbine in the world. At the recent WindEnergy trade exhibition in Hamburg, Germany, the Schaeffler Group showcased a variety of innovative bearings for wind turbines. Gunnar Simm, Head of Application Engineering and product design at Schaeffler Group Industrial's Power Transmission and Railway Division comments: 'In bearing development for wind turbines, it is very important to take into account the entire wind turbine system with all its various interacting drive train components'. 'This makes it possible to significantly increase the reliability and economic efficiency of wind turbines'. 'The bearings used for wind turbines are becoming larger and larger, which is why we start by closely studying the operating conditions, for example, through measurement campaigns'. 'Together with the customer, we work out failure mode and effects analyses in order to minimise potential risks', he continues. With wind turbines, maintenance involves a huge amount of costly logistical effort, for example, ensuring that heavy duty cranes are available. In an offshore environment, costs can increase even further due to higher turbine outputs, therefore higher potential downtime losses and higher weights of parts that need replacing. In May this year, the Schaeffler Group's condition monitoring and maintenance management services division, FAG Industrial Services (FIS), was awarded a contract for the online condition monitoring of Multibrid's first M5000 offshore wind turbine prototype in Bremerhaven, Germany. With the help of numerous sensors, FIS will use its FAG WiPro system to continuously monitor the bearing supports, in terms of vibration, temperature and movement. Any data that deviates from set parameters will be evaluated by specialist staff and appropriate steps taken, helping to avoid unplanned downtime and making it easier to plan ahead for maintenance operations. The FAG WiPro system is also suitable for monitoring wind farms with a large number of wind turbines. At the WindEnergy show, the Schaeffler Group also showcased its plummer block housing for the main rotor support on 1.5MW turbines. This unit consists of a spherical roller bearing with shaft nut as well as additional parts and has been adapted for use in wind turbines. The bearing accommodates loads in all directions, compensates for minor shaft misalignment and deflection, and enables easy relubrication and installation, ensuring high reliability and long life.