Patent ID: 6770988
Filing Date: 2004-08-03
Classification: H02K

Abstract:
A linear electromagnetic machine for generating a force acting between first and second members relatively movable along an axis,said first member constituting a stator of said machine, said second member constituting an armature of said machine, one of the said two members including at least one magnet orientated with its direction of magnetisation substantially parallel to said axis of relative movement and having associated pole pieces, the other of said two members having a conductor in which an electric current can be caused to flow, wherein said magnet is annular in form and there is included a ferromagnetic sleeve on that side of said magnet which is remote from the conductor, said pole pieces having a circumferential surface from which a radial magnetic field extends, said radial magnetic field intersecting said conductor of said other member perpendicularly of the direction in which said electric current flows, whereby to generate a force between said two members acting substantially parallel to said axis, the length of said armature along said axis is less than the length of said stator, and an outer casing is provided for resisting the escape of magnetic fields generated within the machine.