Modern wind turbines utilize hydraulic pitch systems to adjust blade angles. The WUNF 400 actuator is a favorite among OEMs for the blade pitch mechanism. The fine thread (WUNF) resists the micro-vibrations (fretting) caused by turbulent wind, while the 400 kN rating provides the brute force needed to overcome aerodynamic torque.
TPU is sensitive to ozone. If the WUNF 400 sits idle in a warehouse near electric motors (which generate ozone) for 2+ years, surface cracks will appear. Store seals in dark, sealed bags away from motors. wunf 400