Engineering to meet the challenges of the wind industry ‑ effects of increasing size

As turbine sizes continue to increase, farms move further offshore making installation and maintenance operations more complex and returns from generating are squeezed across the sector, every marginal gain that can be made is being welcomed by OEMs, operators and MROs.

Increasing size
With loads on the main shaft of a large wind turbine being high enough to cause flexing and distortion of bearings, it falls to the seal to cope with any eccentricity of movement whilst still performing its intended duties of preventing the escape of lubricant or the ingress of contamination.

By breaking existing rotary seal designs down into their ‘constituent parts’ and making small but significant improvements in each of these areas, James Walker has taken an already successful and proven product and pushed it to deliver new levels of reliability and performance to meet customer demands.

Patented design
What is required for the latest large diameter turbine shafts is a more adaptive sealing assistance that can accommodate fluctuations and still maintain a consistent lip load at all points around the surface of the shaft. The design of our patented Walkersele X-Gen seals has achieved the required high levels of leakage control even where shaft eccentricity exists, whilst the material choice and construction of this new product offers optimised frictional performance and longevity to help in keeping total costs of ownership as low as possible.

Product development and validation testing has all been carried out in‐house at the James Walker centre of excellence for elastomeric materials in the UK. Further real‐life simulation testing was then carried out by OEMs using commercially produced seals on full‐size housing / shaft / bearing set‐ups to test factors such as seal rotation in the housing, lip load, leakage performance and life expectancy.

Further development
With the patented X-Gen seal now deployed on operational turbines and specified for the next generation of turbine products, further variants, which have enhanced performance to meet customer feedback and the specific needs of their latest turbine designs, are now undergoing development and testing.