A novel magnetic harmonic gear

Magnetic gears offer several advantages compared to mechanical gears, in terms of reduced maintenance, improved reliability and inherent overload protection, whilst having a high efficiency. The paper describes the principle of operation of a novel form of magnetic gear, which is particularly suited to applications for which a high gear ratio is required. The performance capability of such a magnetic gear is investigated, and it is shown that it transmits a ripple-free torque, and that a torque density of up to 110 kNm/m can be achieved when high- energy permanent magnets are employed.