In general, only a portion of the rollers in the running bearing bear the load simultaneously, and the area where these rollers are located is called the bearing's load-bearing area. The size of the load bearing bears and the size of the running clearance will have an impact on the bearing area. If the bearing area is too small, the roller is prone to slipping during actual operation.

For wind power gearboxes, if the design of the main shaft adopts a dual bearing support scheme, theoretically only torque is transmitted to the gearbox. In this case, after a simple force analysis, it is not difficult to find that the load borne by the planetary carrier support bearing is relatively small, so the bearing's bearing area is often small, and the rollers are prone to slipping. In the design of wind power gearboxes, the planetary support bearings generally adopt the scheme of two single row tapered bearings or two full roller cylindrical bearings.