Chiến lược thiết kế NSK nâng cao hiệu suất Tuốc Bin gió ngoài khơi.

NSK design strategies enhance the performance of offshore wind turbines

                                  Location of the main rotor bearings in gearless wind turbine systems

Two key factors are demanded of bearings used in wind energy systems: high performance and high service life under harsh conditions. This observation is especially the case in the offshore segment, where the capacities of wind turbines are still increasing. As a result, NSK recently commenced the manufacture of bearings for 9.5 MW turbines and is already developing bearings for offshore turbines in the 12 MW class.

          A major trend in the wind turbine industry is the integration of planetary gear stages and multi-row bearings

Service life expectations rise

Increasing demands are being placed on the operating lifespan of bearings for wind turbines. For onshore turbines, manufacturers traditionally specified that bearings must be designed for a service life of 175,000 hours, which is equivalent to 20 years. However, as a result of the high investment costs and difficulty in accessing offshore wind energy systems, a service life of 25 years is specified, which is a major challenge considering the extremely high dynamic loads.

Main bearings

These loads clearly have an influence on the choice of bearings. In direct-drive wind turbines, double-row tapered roller bearings are increasingly being chosen as the main bearing. Compared with cylindrical roller bearings, which were commonly specified in the past, tapered roller bearings offer the advantage of adjustable pre-load, which makes it possible to achieve higher system rigidity. Such bearings have inner diameters of up to 2.7 m, which challenges even state-of-the-art design and manufacturing concepts.

In the case of geared systems, the weight of the additional drive components is compensated by the fact that the generator can have a smaller design. There are different design concepts for the main rotor bearing in each power capacity class. Systems up to 5 MW usually employ spherical roller bearings, while for 6 MW and higher, the preference is for arrangements with two tapered roller bearings, or double-row tapered roller bearings combined with a cylindrical roller bearing.