Linear electromagnetic machine
First Claim
1. A linear electromagnetic machine comprising:
- means defining a stator;
a coil mounted on said stator;
a reciprocating element having permanent magnet material with magnetized segments of alternating polarity so that reciprocation of said element relative to said stator in an axial direction causes periodic flux reversal through said coil to induce an alternating voltage therein, said magnetized segments being of equal axial extent and being axially spaced by transitional regions that are of axial extent substantially less than that of said magnetized segments; and
flux return means associated with said stator for providing a relatively low reluctance magnetic path for flux lines resulting from the magnetization of said permanent magnet material wherein the reluctance is generally independent of the position of said reciprocating element.
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Accused Products
Abstract
A linear electromagnetic machine has a stator with a coil mounted thereon. A reciprocating element has permanent magnet segments of alternating polarity so that reciprocation of said element relative to said stator in an axial direction causes periodic flux reversal through the coil to induce an alternating voltage therein. The magnetized segments are of equal axial extent and are axially spaced by transitional regions that are of axial extent substantially less than that of the magnetized segments. Flux return and core elements associated with the stator provides a relatively low reluctance magnetic path for flux lines resulting from magnetization of the permanent magnets wherein the reluctance is generally independent of the position of the reciprocating element.
121 Citations
17 Claims
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1. A linear electromagnetic machine comprising:
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means defining a stator; a coil mounted on said stator; a reciprocating element having permanent magnet material with magnetized segments of alternating polarity so that reciprocation of said element relative to said stator in an axial direction causes periodic flux reversal through said coil to induce an alternating voltage therein, said magnetized segments being of equal axial extent and being axially spaced by transitional regions that are of axial extent substantially less than that of said magnetized segments; and flux return means associated with said stator for providing a relatively low reluctance magnetic path for flux lines resulting from the magnetization of said permanent magnet material wherein the reluctance is generally independent of the position of said reciprocating element. - View Dependent Claims (2, 3, 4)
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5. An electromagnetic machine comprising:
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a stator defining an annular bore, the central region of said stator including at least one coil mounted axially with respect to said bore and radially inboard therefrom; a reciprocating element including a tubular permanent magnet having multiple magnetic poles of alternating radial polarity; means defining a gas spring acting on said reciprocating element, the effective spring coefficient of said gas spring and the mass of said reciprocating element defining a resonant frequency; and means for varying said effective spring coefficient to permit control of the operating frequency. - View Dependent Claims (6, 7, 8)
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9. Apparatus for generating an alternating voltage output comprising:
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means defining a stator; a coil mounted on said stator; a reciprocating element having permanent magnet material with segments of alternating polarity so that reciprocation of said element relative to said stator causes periodic flux reversal through said coil to induce an alternating voltage therein; flux return means associated with said stator defining a relatively low reluctance magnetic path wherein the reluctance is generally independent of the position of said reciprocating element; a Stirling engine having a displacer piston; means defining a working fluid chamber in fluid communication with a first side of said displacer piston and with a first side of said reciprocating element; means defining a bounce fluid chamber in fluid commmunication with a second side of said reciprocating element; said working fluid chamber and said bounce fluid chamber defining a gas spring acting on said reciprocating element; the effective spring coefficient of said gas spring and the mass of said reciprocating element defining a resonant frequency; means for varying said effective spring coefficient in response to feedback signals representative of the phase and frequency relationship between said alternating voltage and a standard alternating voltage to permit control of the operating frequency; and means responsive to the voltage output of said apparatus for providing variable damping of said Stirling engine displacer; whereupon the stroke of said displacer may be varied to maintain voltage regulation of said output. - View Dependent Claims (10, 11)
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12. A linear electromagnetic machine comprising:
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means defining a stator; a plurality of coils mounted on said stator and disposed at a predetermined center-to-center axial spacing; a reciprocating element having permanent magnet material with magnetized segments of alternating polarity, said segments being disposed at one-half said predetermined center-to-center axial spacing, so that reciprocation of said element relative to said stator causes periodic flux reversal through said coils to induce an alternating voltage therein; and flux return means associated with said stator for providing a relatively low reluctance magnetic path for flux lines resulting from the magnetization of said permanent magnet material wherein the reluctance is generally independent of the position of said reciprocating element. - View Dependent Claims (13, 14, 15)
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16. A linear electromagnetic machine comprising:
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a stator defining an annular bore; a plurality of coils mounted to said stator and disposed at a center-to-center axial spacing therealong and radially inboard from said bore; a reciprocating element having permanently magnetized cylindrical segments of alternating polarity, which segments are disposed at one-half the center-to-center spacing of said coils, so that axial reciprocation of said reciprocating element relative to said stator causes periodic flux reversal through said coils to induce an alternating voltage therein; and flux return means associated with said stator for providing a relatively low reluctance magnetic path for the flux lines resulting from the magnetization of said reciprocating element wherein the reluctance is generally independent of the position of said reciprocating element. - View Dependent Claims (17)
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Specification