Abstract
The implementation of a magnetic bearing within a high-speed, high-capacity SPM motor (450kW, 17,000rpm) and the subsequent elimination of the step up gear from the centrifugal compressor have achieved increased efficiency, size reduction, and oil-free design of large HVAC chillers. This report examines the characteristics of magnetic bearings and describes the higher radial suspension force technology that allows for a shorter bearing length, key to achieving higher speeds and compressor size reduction. The report also introduces features of the large centrifugal chiller units containing the newly developed magnetic bearing in the US and China markets.
