What types of loads are bearings in a wind turbine subject to?

• A. Thrust and tangential
• B. Thrust and radial loads
• C. Torsional and bending
• D. Shear and tensile

Answer: (B)

Bearings on a wind turbine shaft must resist two main kinds of forces: axial (along the shaft) and radial (perpendicular to the shaft). The axial load, or thrust, comes from wind pushing on the blades and generating a forward push on the rotor that the bearing must transmit up the shaft. The radial load comes from bending moments caused by the rotor’s weight, wind gusts, and dynamic blade loads, which push the shaft sideways relative to the bearings. Together, these two components—thrust (axial) and radial—describe the primary loading a turbine bearing is designed to handle. The other options mix in loads that aren’t the fundamental bearing reactions in this context, like pure torsion, tangential forces, or purely tensile/shear loads.