Vertical and horizontal wind shears, yaw misalignment and/or turbulence act together to produce asymmetric loading across a wind turbine rotor. The resultant load produces bending moments in the blades that are reacted through the hub and subsequently to the main shaft. As a result, the main shaft may...http://www.google.ca/patents/US7004724?utm_source=gb-gplus-sharePatent US7004724 - Method and apparatus for wind turbine rotor load control based on shaft radial displacement
