Patent ID: 8310113

Claim:
An electromagnetic, reciprocating linear motor or alternator including a reciprocatable actuator having an axis of reciprocation, a nominal design stroke and a mean position, the linear alternator or motor comprising: (a) at least two armatures that are adjacent along the axis, each armature having an associated armature winding and an associated core forming a low reluctance magnetic flux loop, each core loop having a pair of spaced gaps that are aligned parallel to the axis and separated by an armature winding slot, each gap defined by two opposed pole faces, the gaps of the armatures being linearly aligned along a gap path parallel to the axis; and (b) field magnets mounted to the actuator for reciprocation within the gap path, the field magnets including (i) a plurality of main field magnets, each main field magnet associated with an armature, each main field magnet extending in an axial direction from within one gap of its associated core to within the other gap of its associated core, the main field magnets having a magnetic polarization in the same direction across the gap path; (ii) at least one secondary magnet extending in an axial direction and mechanically mounted for reciprocation with the main magnets within the gap path, a secondary magnet being interposed between the main magnets and extending in an axial direction from within a gap of one core to within an adjacent gap of an adjacent core, each secondary magnet being magnetically polarized in a direction opposite the polarization of the main magnets.