Rotary-to-Linear Magnetic Gear

The paper introduces a permanent magnet rotary-to-linear magnetic gear whose topology is derived based on the operating principle of a transverse flux VRPM machine. It is shown that when the number of poles per unit length on all three members, rotor, translator and stationary flux modulating ferromagnetic pieces, are the same, the proposed gear is essentially similar to a magnetic screw gear with discretised helical magnets. Using different number of poles and iron pieces per unit length provides alternative means for adjusting the gear ratio. The paper describes the design and construction of a demonstrator gear whose dimensions were optimised using finite element analysis. Performance results obtained from finite element analysis and experiment are presented and discussed.