Patent ID: 8232689
Filing Date: 2012-07-31
Classification: H02K,Y02E

Abstract:
1. An electromagnetic machine comprising: a magnetic part having a first portion and a second portion disposed in spaced relationship to the first portion, the magnetic part being arranged to provide a regular spatially periodic magnetic field across an air gap between the first portion and the second portion; and an electrical part disposed in the air gap between the first and second portions of the magnetic part and arranged to move relative to the magnetic part, the electrical part comprising a set of insulated patterned laminar conductors which intercept the spatially periodic magnetic field, the set of insulated laminar conductors being patterned to form transverse conducting paths lying perpendicular to both the magnetic field and the direction of relative motion of the electrical and magnetic parts, the transverse conducting paths being connected at their ends by axial conducting paths, the insulated patterned laminar conductors being arranged to form a plurality of phases through which separate electrical currents are arranged to pass, the relative signs and amplitudes of the currents being controlled so as to determine the magnitude and sign of the electromagnetic force produced by the machine; wherein the transverse conducting paths each have a dimension along or parallel to the direction of relative motion that is approximately equal to but less than one sixth of the length of the magnetic period of the spatially periodic magnetic field, the axial conducting paths being arranged to cause the current in the conductors to flow alternately back and forth transverse to the direction of relative motion with a spatial period equal to one half of the magnetic period, the transverse conducting paths of the phases being interdigitated in the region of the spatially-periodic magnetic field and the axial conducting paths overlapping one another outside the region of the spatially-periodic magnetic field.