Can body maker with linear motor redraw actuator

A linear motor having an armature movable relative to a stator, comprising:

• a plurality of axially spaced apart salient poles on the armature;
• an axially polarized permanent magnet situated between each adjacent pair of armature salient poles;
• a plurality of axially spaced apart salient poles on the stator, wherein the axial spacing between adjacent stator salient poles is greater than the axial spacing between adjacent armature salient poles;
• an electromagnetic coil situated between each adjacent pair of stator salient poles;
• control means for sequentially energizing the electromagnetic coils to generate a translating magnetic field wave that interacts with the armature salient poles to produce translatory motion of the armature relative to the stator;
• said armature salient poles each form a ring surrounding a portion of the armature, and wherein each axially polarized permanent magnet forms a ring surrounding an adjacent portion of the armature;
• and
• said armature includes a non-magnetic sleeve underlying the armature salient pole rings and the permanent magnet rings.

An electromagnetic linear motor having an armature movable relative to a coaxial stator, the linear motor comprising:

• a plurality of axially spaced apart salient poles on the armature, wherein each armature salient pole forms a ring surrounding an underlying portion of the armature;
• an axially polarized permanent magnet situated between each adjacent pair of armature salient poles, each permanent magnet forming a ring surrounding an adjacent underlying portion of the armature and being oppositely polarized with regard to each adjacent permanent magnet ring;
• a plurality of axially spaced apart salient poles on the stator, each forming a ring surrounding a portion of the armature, wherein the axial spacing between adjacent stator salient poles is greater than the axial spacing between adjacent armature salient poles;
• an electromagnetic coil situated between each adjacent pair of stator salient poles, wherein each electromagnetic coil extends circumferentially around a portion of the armature between the adjacent pair of stator salient poles;
• means for sequentially energizing the electromagnetic coils to generate a translating magnetic field wave to produce translatory motion of the armature relative to the stator, wherein the electromagnetic coils are all energized continuously with sinusoidally varying currents;
• and
• said electromagnetic coils generate magnetic flux having the same polarity as magnetic flux generated by the permanent magnets between facing armature and stator salient poles positioned to move the armature relative to the stator in a desired direction, and magnetic flux having an opposite polarity as magnetic flux generated by the permanent magnets between facing armature and stator salient poles positioned to resist movement of the armature relative to the stator in the desired direction.

An electromagnetic linear motor having a generally cylindrical armature movable relative to a stator, the linear motor comprising:

• a plurality of axially spaced apart salient poles on the armature, wherein each armature salient pole forms a ring surrounding an underlying portion of the armature;
• an axially polarized permanent magnet situated between each adjacent pair of armature salient poles, each permanent magnet forming a ring surrounding an adjacent underlying portion of the armature and being oppositely polarized with regard to each adjacent permanent magnet ring;
• a non-magnetic sleeve underlying the armature salient pole rings and the permanent magnet rings;
• a plurality of axially spaced apart salient poles on the stator, each forming a ring surrounding a portion of the armature, wherein the axial spacing between adjacent stator salient poles is one-third greater than the axial spacing between adjacent armature salient poles;
• at least six electromagnetic coils each being situated between a respective adjacent pair of stator salient poles and extending circumferentially around a portion of the armature, the electromagnetic coils being connected in three primary pairs, wherein each pair of electromagnetic coils has a 120 degree current phase difference with respect to the other two primary pairs of electromagnetic coils, when energized;
• and
• means for continuously energizing the electromagnetic coils and varying the phasing and polarity of the current through the electromagnetic coils to generate a translating magnetic field wave to produce translatory motion of the armature relative to the stator.