Patent ID: 6608408
Filing Date: 2003-08-19
Classification: H02K

Abstract:
A linear electromagnetic machine for generating a force acting between at least two members relatively movable along an axis, at least one of said two members is capable of producing a magnetic field the direction of at least part of which extends substantially radially of the said axis and intersects a conductor of which the other member comprises or includes and in which an electric current can flow substantially perpendicularly with respect to that part of said magnetic field intersecting it whereby to generate a force between said two members substantially parallel to said axis, characterized in that said means for generating the radial magnetic field comprises a permanent magnet oriented with its direction of magnetization substantially parallel to said axis associated with pole pieces for its north and south poles from circumferential surfaces of which the generally radial magnetic field extends to intersect the coil, and that the magnets are annular magnets and an associate ferromagnetic sleeve closing the magnetic path between opposite pole pieces of each magnet engages a cylindrical surface of the magnets opposite to which faces the conductor.