Feasibility analysis of a novel conical plain bearing with rotating segments as wind turbine main bearing

Abstract

Abstract Further expansion of wind energy is a key aspect for the transition towards renewable energy production. Operational expenditures constitute a significant portion of the cost of wind energy. One key aspect within these costs are maintenance costs. Main bearings of wind turbines suffer from comparably high failure rates. The exchange of a wind turbine main bearing is especially costly, as the rotor is dismounted and the drivetrain needs to be dismantled. Currently all commercially available wind turbine main bearings are roller bearings. One approach to reduce the operational costs is to develop segmented plain bearings as wind turbine main bearings. The segmented design allows for repair on tower without dismantling the drivetrain. In this work a novel, flexible plain bearing concept as wind turbine main bearing is presented. Key feature of this novel concept are its sliding segments that are mounted to the rotating main shaft. In contrast to designs which segments are mounted to the still standing housing, the rotatable shaft allows the segments to be rotated into intended positions for inspections or maintenance. In case of failure, faulty segments can be exchanged in a preferred service position, which provides easy access. The novel concept is evaluated using elasto-hydrodynamic-multi-body simulations and compared to the already established FlexPad concept.