Alternator
First Claim
1. An alternator comprising:
- a rotor for forming north-seeking (N) and south-seeking (S) poles about a rotational circumference;
a stator comprising;
a stator core disposed facing said rotor; and
a polyphase stator winding installed in said stator core; and
a bracket supporting said rotor and said stator, wherein said stator core comprises a laminated iron core formed with a number of slots extending axially at a predetermined pitch in a circumferential direction, said polyphase stator winding comprises a number of winding sub-portions in each which a long strand of wire is wound so as to alternately occupy an inner layer and an outer layer in a slot depth direction within said slots at intervals of a predetermined number of slots, said strand of wire folding back outside said slots at axial end surfaces of said stator core to form turn portions, and said turn portions align in a circumferential direction to constitute coil end groups at both axial end portions of said stator core, wherein said number of winding sub-portions are constructed with at least one winding assembly formed by simultaneously bending and folding a plurality of said strand of wires, wherein said winding assembly is constructed by arranging at one slot pitch offset the same number of wire-strand pairs as said predetermined number of slots, each of said wire-strand pairs constructed by arranging two strands of said strands of wire so that straight portions alternately overlap at a predetermined pitch, each of said strands of wire being formed into a pattern in which said straight portions are connected by turn portions so as to be arranged at a pitch of said predetermined number of slots and adjacent straight portions are offset by said turn portions so as to alternately occupy said inner layer and said outer layer in said slot depth direction, and by extending each end portion of said strands of wire on both sides of both ends of said winding assembly and arranging the same number of pairs of said overlapping straight portions as the number of said slots at said one slot pitch.
1 Assignment
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Accused Products
Abstract
An alternator includes a rotor for forming north-seeking (N) and south-seeking (S) poles about a rotational circumference, a stator having a stator core disposed facing the rotor and a polyphase stator winding installed in the stator core, and a bracket supporting the rotor and the stator, wherein the stator core includes a laminated iron core formed with a number of slots extending axially at a predetermined pitch in a circumferential direction, the polyphase stator winding includes a number of winding sub-portions in each which a long strand of wire is wound so as to alternately occupy an inner layer and an outer layer in a slot depth direction within the slots at intervals of a predetermined number of slots, the strand of wire folding back outside the slots at axial end surfaces of the stator core to form turn portions, and the turn portions align in a circumferential direction to constitute coil end groups.
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Citations
27 Claims
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1. An alternator comprising:
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a rotor for forming north-seeking (N) and south-seeking (S) poles about a rotational circumference;
a stator comprising;
a stator core disposed facing said rotor; and
a polyphase stator winding installed in said stator core; and
a bracket supporting said rotor and said stator, wherein said stator core comprises a laminated iron core formed with a number of slots extending axially at a predetermined pitch in a circumferential direction, said polyphase stator winding comprises a number of winding sub-portions in each which a long strand of wire is wound so as to alternately occupy an inner layer and an outer layer in a slot depth direction within said slots at intervals of a predetermined number of slots, said strand of wire folding back outside said slots at axial end surfaces of said stator core to form turn portions, and said turn portions align in a circumferential direction to constitute coil end groups at both axial end portions of said stator core, wherein said number of winding sub-portions are constructed with at least one winding assembly formed by simultaneously bending and folding a plurality of said strand of wires, wherein said winding assembly is constructed by arranging at one slot pitch offset the same number of wire-strand pairs as said predetermined number of slots, each of said wire-strand pairs constructed by arranging two strands of said strands of wire so that straight portions alternately overlap at a predetermined pitch, each of said strands of wire being formed into a pattern in which said straight portions are connected by turn portions so as to be arranged at a pitch of said predetermined number of slots and adjacent straight portions are offset by said turn portions so as to alternately occupy said inner layer and said outer layer in said slot depth direction, and by extending each end portion of said strands of wire on both sides of both ends of said winding assembly and arranging the same number of pairs of said overlapping straight portions as the number of said slots at said one slot pitch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
wherein said rotor comprises: a Lundell-type rotor core having a number of claw-shaped magnetic poles providing said north-seeking (N) and south-seeking (S) poles; and
a cooling means for supplying cooling air inside said bracket by rotation of said rotor, whereby said coil end groups and said rectifier are cooled by passage of said cooling air inside said bracket.
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14. The alternator according to claim 13 wherein said cooling means is a fan disposed on at least one axial end portion of said rotor core.
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15. The alternator according to claim 14 wherein said fans are disposed on both axial end portions of said rotor core.
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16. The alternator according to claim 13 wherein an axial length of said stator including said coil end groups is shorter than an axial length of said rotor core.
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17. The alternator according to claim 13 wherein directions of inclination of said strands of wire constituting inner circumferential sides of said coil end groups are parallel at both axial ends of said stator.
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18. The alternator according to claim 13 wherein:
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a number of slots housing said polyphase stator winding is two per pole per phase; and
said polyphase stator winding comprises a first polyphase winding portion and a second polyphase winding portion each corresponding to one slot per pole per phase.
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19. The alternator according to claim 18 wherein said first polyphase winding portion and said second polyphase winding portion are connected in series and winding ends thereof are connected to said rectifier.
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20. The alternator according to claim 18 wherein said rectifier comprises:
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a first rectifier for converting alternating-current output from said first polyphase winding portion; and
a second rectifier for converting alternating-current output from said second polyphase winding portion, output from said first polyphase winding portion and said second polyphase winding portion being combined after being converted separately by said first and second rectifiers.
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21. The alternator according to claim 18 wherein each of said first and second polyphase winding portions is a three-phase connection,
opening portions of slots constituting a slot group into which said first polyphase winding portion is inserted and opening portions of slots constituting a slot group into which said second polyphase winding portion is inserted being arranged at an even pitch corresponding to an electrical angle of 30° - .
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22. The alternator according to claim 18 wherein each of said first and second polyphase winding portions is a three-phase connection,
opening portions of slots constituting a slot group into which said first polyphase winding portion is inserted and opening portions of slots constituting a slot group into which said second polyphase winding portion is inserted being arranged so as to alternate between an electrical angle of (α - °
) and an electrical angle of (60°
−
α
°
).
- °
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23. The alternator according to claim 18 wherein at least one of said first and second polyphase winding portions is a star-connection and a neutral point of said star connected polyphase winding portion is connected to said rectifier.
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24. The alternator according to claim 13 wherein a field current flowing to a field coil for supplying a magnetic field to said claw-shaped magnetic poles is limited when rotational frequency of said alternator is greater than or equal to a predetermined value.
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25. The alternator according to claim 13 wherein magnets are interposed between said claw-shaped magnetic poles.
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26. An alternator comprising:
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a rotor for forming north-seeking (N) and south-seeking (S) poles about a rotational circumference;
a stator comprising;
a stator core disposed facing said rotor; and
a polyphase stator winding installed in said stator core; and
a bracket supporting said rotor and said stator, wherein said stator core comprises a laminated iron core formed with a number of slots extending axially at a predetermined pitch in a circumferential direction, said polyphase stator winding comprises a number of winding sub-portions in each which a long strand of wire is wound so as to alternately occupy an inner layer and an outer layer in a slot depth direction within said slots at intervals of a predetermined number of slots, said strand of wire folding back outside said slots at axial end surfaces of said stator core to form turn portions, and said turn portions align in a circumferential direction to constitute coil end groups at both axial end portions of said stator core, wherein 2n strands of said strands of wire are disposed in a row in said depth direction in each of said slots; and
said turn portions of said strands of wire are arranged so as to align into n rows in a circumferential direction.
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27. An alternator comprising:
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a rotor for forming north-seeking (N) and south-seeking (S) poles about a rotational circumference;
a stator comprising;
a stator core disposed facing said rotor; and
a polyphase stator winding installed in said stator core; and
a bracket supporting said rotor and said stator, wherein said stator core comprises a laminated iron core formed with a number of slots extending axially at a predetermined pitch in a circumferential direction, said polyphase stator winding comprises a number of winding sub-portions in each which a long strand of wire is wound so as to alternately occupy an inner layer and an outer layer in a slot depth direction within said slots at intervals of a predetermined number of slots, said strand of wire folding back outside said slots at axial end surfaces of said stator core to form turn portions, and said turn portions align in a circumferential direction to constitute coil end groups at both axial end portions of said stator core, wherein 2n strands of said strands of wire are disposed in a row in said depth direction in each of said slots; and
said turn portions of said strands of wire are arranged so as to stack up into n layers, where n is an integer which is equal to or more than 2.
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Specification