Evaluation of a magnetic gear for air-cooled condenser applications

In high-power industrial applications such as air-cooled condenser fans, excessive mechanical gear failures highlight a need to investigate possible alternatives. In this study, the concentric magnetic gear (CMG) is evaluated as a potential replacement for traditional mechanical gear. For a more objective comparison between the CMG and mechanical gear, a CMG is optimally designed in accordance with the performance specifications of an existing mechanical gear. The design is further refined for performance improvements taking into account mechanical strength requirements. Based on the design a CMG prototype is manufactured and experimentally evaluated against its mechanical counterpart under the same operating conditions. The performance of both gears achieved efficiency in the mid 90% range. The mechanical gear slightly outperformed the CMG under rated operating conditions. The large unbalanced magnetic forces within the CMG are likely responsible for the larger than expected no-load losses. With the advantage of overload protection, reduced maintenance requirements, the CMG could be a valid replacement for the mechanical gear.