Linear electromagnetic machine
AssigneeAdvanced Motion Technologies Corp.
InventorPhillip Raymond Michael Denne
Life of this patent
Estimating the term…
Abstract
A linear electromagnetic machine for generating a force acting between two members relatively movable along an axis, one of which is capable of producing a magnetic field the direction of at least part of which extends substantially radially of the said axis and the other of which comprises or includes a conductor, conveniently in the form of a coil, in which an electric current can flow substantially perpendicularly of the magnetic field so as to generate a force between the two members substantially parallel to the axis. The radial magnetic field is generated by permanent magnets orientated with their direction of magnetization axially, the pole pieces acting to concentrate the magnetic flux to follow a radial path through the coils.
Claims28
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.
A linear electromagnetic machine of the type comprising a stator having a plurality of axially aligned and oriented coils, an armature generating a radial magnetic field and control means for controlling the magnitude and direction of electric currents in the said coils whereby to generate a force between the armature and the stator, characterised in that the armature has associated therewith a transducer for determining at least one of its position, velocity or acceleration, and the magnitude and direction of the current applied to any one coil by the said control means is determined by the output from the said transducer.
A linear electromagnetic machine adapted for use with a three phase supply, comprising a stator having a plurality of coils aligned along a common axis, an armature having means for producing a magnetic field extending radially of the said axis and control means for applying electrical currents to the coils the magnitude and direction of which results in the generation of a force between the armature and the stator substantially parallel to the said axis, characterised in that the magnetic field produced by the armature comprises at least two regions of opposite polarity defining the magnetic field period and the axil dimensions of each coil is substantially one sixth of the magnetic period of the armature.
Dependencies are inferred from the claim text.