Can a yaw bearing be selected from axial load capacity alone?

The short answer

No. A yaw slewing bearing can carry combined axial force, radial force and tilting moment. A headline axial capacity does not describe that combination. Selection requires the manufacturer’s method and the actual simultaneous interface loads for the proposed wind-turbine configuration.

Keep concurrent loads in one case

Do not take axial force from one operating condition and a favorable moment from another and call the pair a real load case. Identify directions, reference point and which loads occur together. An offset force can also contribute to the reported moment. Before using a selection chart, confirm that its load definitions match the interface load package and that any required combination factors have been applied correctly.

Read the chart boundary precisely

A chart can represent raceway capacity, fastening capacity or another assessed limitation under specified support conditions. Being below one curve cannot establish every part of the assembly. The calculation may also require treatment of radial force or dynamic duty beyond the plotted axes. Catalogue geometry and support assumptions should be checked before a chart from one bearing size or series is used for another.

Request the complete selection package

Ask for bearing identity, simultaneous load cases, applicable curves/calculations and the assumed connecting-structure conditions. Have the supplier identify which check governs and which limits require separate verification. Rothe Erde provides slewing-bearing engineering guidance, not MARSTON bearing capacity. Neither turbine rated kW nor an isolated axial rating proves suitability. The decision is whether the actual bearing and mounted arrangement cover the full documented force-and-moment envelope without unsupported extrapolation from a single catalogue number. A selection chart’s bolt and raceway curves can govern different cases. The designer should identify which boundary is being compared rather than treat a favorable result on one curve as a complete mounted-bearing assessment.