Patent ID: 8922093

Claim:
An axial flux motor assembly comprising: a stack of first and second discs arranged alternately such that there is a gap allowing rotation between each disc, there being at least one first disc and at least one second disc in the stack; each said first disc being mounted so as to be rotatable; and each said second disc being fixed in position, wherein each of the first and second discs comprises sectors of magnetic material arranged on a face of the disc, between each of which sectors is a radially-extending section of a conductive path for conducting electric current, the sectors of magnetic material on each first disc being arranged at a first constant pitch, and the sectors of magnetic material on each second disc being arranged at a second constant pitch, where the said first and second constant pitches are not equal, wherein, when the assembly is in use: the polarities of the currents flowing in adjacent sections of the conductive path in one of each first disc or each second disc are mutually opposite for all sections, and the polarities of the currents flowing in adjacent sections of the conductive path in the other of each first disc or each second disc are mutually opposite for all sections except for two sections on either side of a current feed point where they are the same; magnetic flux in the one of each first disc or each second disc runs perpendicular to the faces of the discs in axially-extending flux paths, such that, considering each first disc independently of each second disc, the magnetic flux in one axially-extending flux path runs in an opposite direction to that in the immediately-adjacent flux paths on each side of it, and is returned by flux return portions of magnetic material provided at each end of the assembly; magnetic flux in the other of each first disc or each second disc runs perpendicular to the faces of the discs in axially-extending flux paths, such that, considering each first disc independently of each second disc, the magnetic flux in one axially-extending path runs in an opposite direction to that in the immediately-adjacent flux paths on each side of it except for magnetic sectors bound by currents from a feed point, and is returned by the flux return portions of magnetic material provided at each end of the assembly; and in each case the total flux is the super-position of the flux of each first disc and each second disc, and wherein the assembly comprises switching circuitry for progressively changing selected feed point connections in the other of each first disc or each second disc in correspondence to rotation thereof relative to the one of each first disc or each second disc in such a way as to effect continuous rotation of each first disc.