Patent ID: 7560845

Claim:
A rotor for a variable reluctance machine, the rotor defining an axis of rotation about which the rotor can rotate, said rotor comprising: a core portion comprising magnetizable material; and at least two rotor poles, each pole having: an axial extent parallel to the axis, said axial extent being defined by a first and a second axial end of the rotor pole, and a radial extent at right angles to the axis, said radial extent being defined by a radially inner face and a radially outer face of the rotor pole, each rotor pole being attached to the core portion at the first axial end, wherein at least the rotor poles are made from unlaminated magnetizable material, the core portion forms part of a magnetic circuit of a phase of the variable reluctance machine and the magnetic circuit extends from a first rotor pole of the rotor poles into the core portion and from the core portion into a second rotor pole of the rotor poles, said second rotor pole being diametrically opposite said first rotor pole, and wherein the radially inner faces of the rotor poles define a space, the space having no magnetizable material therein.