Patent ID: 8482171

Claim:
A magnetic gear arrangement comprising: a first gear member for generating a first magnetic field, a second gear member for generating a second magnetic field, and a coupling device that provides arrangements of interpoles between the first gear member and the second gear member, the interpoles coupling the first and second magnetic fields such that different arrangements of the interpoles produce different gear ratios between the first and second gear members; wherein: the coupling device comprises a plurality of ferromagnetic pole elements that at least partly form the interpoles, each of the plurality of ferromagnetic pole elements having a Curie temperature such that each of the plurality of ferromagnetic pole elements is active below its Curie temperature and inactive above its Curie temperature, and the magnetic gear arrangement further comprises a temperature controller for controlling a temperature of at least some of the plurality of ferromagnetic pole elements such that, under the control of the temperature controller, the temperatures of the plurality of ferromagnetic pole elements can cross their respective Curie temperatures and thereby change from active to inactive or the reverse.