Electrical machine with double excitation, especially a motor vehicle alternator
First Claim
1. An electrical machine, comprising:
- a stator defining at least one pair of stator slots;
at least one armature winding having at least one wire in the stator slots;
a rotor within the stator defining a plurality of rotor poles in circumferential succession and a plurality of rotor slots, each of which lies between two successive poles;
a current adjustment circuit that provides unidirectional adjustable current;
at least two permanent excitation magnets on the rotor for establishing two magnetic fluxes having components in opposite directions in accordance with the direction of displacement of the rotor in the stator, the magnets defining at least one pair of successive magnets; and
at least one excitation winding having two wires received in the rotor slots between the magnets of each pair, the excitation winding coupled to said current adjustment circuit to adjustably produce two components of flux such as to oppose the fluxes produced in the magnets of the pair, the excitation magnets and the excitation windings selectively establishing closed magnetic circuits passing around the armature winding.
1 Assignment
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Accused Products
Abstract
A rotary electrical machine such as a motor vehicle alternator comprises a stator and a rotor. The stator has at least one armature winding in at least one pair of stator slots. The rotor includes means for selectively establishing closed magnetic circuits which pass around the turns of the armature winding or windings. The means for setting up closed magnetic circuits comprise at least two permanent excitation magnets which set up two magnetic fluxes having components in opposite directions according to the direction of displacement of the rotor; and, between each pair of successive magnets, at least one excitation winding having two wires and being arranged to produce in an adjustably way two flux components which are such as to oppose the fluxes set up in the magnets of the pair. The wires of the excitation windings are located in rotor slots, each of which lies between two successive rotor poles.
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Citations
27 Claims
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1. An electrical machine, comprising:
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a stator defining at least one pair of stator slots; at least one armature winding having at least one wire in the stator slots; a rotor within the stator defining a plurality of rotor poles in circumferential succession and a plurality of rotor slots, each of which lies between two successive poles; a current adjustment circuit that provides unidirectional adjustable current; at least two permanent excitation magnets on the rotor for establishing two magnetic fluxes having components in opposite directions in accordance with the direction of displacement of the rotor in the stator, the magnets defining at least one pair of successive magnets; and at least one excitation winding having two wires received in the rotor slots between the magnets of each pair, the excitation winding coupled to said current adjustment circuit to adjustably produce two components of flux such as to oppose the fluxes produced in the magnets of the pair, the excitation magnets and the excitation windings selectively establishing closed magnetic circuits passing around the armature winding. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An electrical machine, comprising:
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a stator defining at least one pair of stator slots, the stator slots defining between them a plurality of stator poles; a wire armature winding mounted in the stator slots; a rotor within the stator defining a plurality of rotor poles associated with the stator poles; a current adjustment circuit that provides unidirectional adjustable current; and permanent excitation magnets and excitation windings, said excitation windings coupled to said current adjustment circuit for selectively establishing closed magnetic circuits passing around the wires of the armature winding via the stator and rotor poles, the rotor poles defining a configuration consisting of alternate successive groups comprising a common odd number greater than one of identical north and south poles, and wherein, when current flows in the excitation windings, the rotor poles define a configuration comprising individual alternate north and south poles.
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12. An electrical machine, comprising:
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a stator defining at least one pair of stator slots, the stator slots defining between them a plurality of stator poles; a wire armature winding mounted in the stator slots; a rotor within the stator defining a plurality of rotor poles associated with the stator poles; a current adjustment circuit that provides unidirectional adjustable current; and permanent excitation magnets and excitation windings, said excitation windings coupled to said current adjustment circuit for selectively establishing closed magnetic circuits passing around the wire of the armature winding via the stator and rotor poles, the rotor poles defining a configuration consisting alternatively of a given individual pole and a succession of opposite poles in an odd number greater than one, and wherein, when current flows in the excitation windings, the rotor poles define a configuration comprising individual alternate north and south poles.
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13. A rotor, comprising:
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a plurality of circumferentially adjacent magnets; a plurality of poles between adjacent magnets extending outwardly in a radial direction, the spaces between the poles forming a plurality of slots; a current adjustment circuit that provides unidirectional adjustable current; and an excitation winding coupled to said current adjustment circuit in the slots adjacent to at least one of the plurality of poles between adjacent magnets, whereas when substantially none of said current flows through the excitation winding, a magnetic field generated by adjacent magnets induces the same polarity on poles between the adjacent magnets, and when more than a threshold level of said current flows through the excitation winding, a combined magnetic field generated by the adjacent magnets and the excitation winding between the adjacent magnets induces opposite polarities on adjacent poles between the adjacent magnets. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. An electrical machine, comprising:
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a stator; a rotor containing a plurality of circumferentially adjacent magnets, the adjacent magnets separated by a plurality of poles; and means for selectively adjusting a unidirectional excitation current to induce either the same polarity on adjacent poles separating the adjacent magnets or opposite polarities on adjacent poles separating the adjacent magnets. - View Dependent Claims (21, 22, 23, 24, 25)
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26. A method for generating power, comprising:
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generating a magnetic field with a plurality of permanent magnets embedded in a rotor of an electrical machine, the magnetic field inducing the same polarity on adjacent poles between successive magnets; and selectively adjusting a unidirectional excitation current coupled to excitation windings embedded in the rotor above a threshold level so that the magnetic field generated by the excitation current in the excitation windings combines with the magnetic field generated by the magnets to induce opposite polarities on adjacent poles between adjacent magnets. - View Dependent Claims (27)
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Specification