Low Cost Rotary-to-Linear Magnetic Gear

A rotary-to-linear PM (permanent magnet) gear is introduced. The topology is initially derived based on the operating principle of a transverse flux machine. It is shown that when the number of poles on all three members, rotor, translator and stationary ferromagnetic pieces are the same, it essentially behaves like that of a magnetic screw gear with helical magnets with the added advantages of ease of manufacture and low cost. Using different number of poles and iron pieces enables the adjustment of the gear ratio, which provides another design variable. The paper describes the design and construction of a demonstrator gear and presents performance results obtained from finite element analysis and experiments.