Wind turbine towers are manufactured by cutting steel plates into segments, rolling them and welding them together. Turbine towers weigh around 1,000 tonnes. During the welding process, the tubular segments are placed on rotators which turn the individual segments so that the parts can be welded together.
In the past, steel wheels were used as rotators due to the high load bearing requirements. The rigid steel wheels caused vibrations during the rotation of the tower, which had a negative impact on the weld seams. This was down to the poor surface quality and lack of roundness in the bent tubular sections.
To combat the vibrations, manufacturers began using wheels with steel wheel centres or cast wheel centres and a polyurethane tread. In order to achieve the required load capacity, at least two wheels were required on an axle. As the weight of the tubular segments increased, the required load capacity could only be achieved by placing four wheels next to one another. The disadvantage of this design is that placing four wheels next to one another puts an enormous load on the axle. Because of this, a significant axle diameter is required to prevent the failure of the axle. The customer was looking for a new solution with only one polyurethane wheel in order to cut material costs and achieve even higher load capacities.