Alternator for an automotive vehicle

• US 5,998,903 A
• Filed: 03/16/1998
• Issued: 12/07/1999
• Est. Priority Date: 05/26/1997
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Umeda, Atsushi, Kusase, Shin, Shiga, Tsutomu
• Primary Examiner(s): LABALLE, CLAYTON E
• Application Number:
  US09/039,480
• Time in Patent Office: 631 Days
• Field of Search: 310/68 D, 310/179, 310/215, 310/184, 310/201, 310/263, 310/58, 310/207, 310/198
• US Class Current: 310/179
• CPC Class Codes: H02K 1/243 of the claw-pole type
• CPC Class Codes: H02K 19/22 having windings each turn of which co-operates alternately with poles of opposite polarity, e.g. heteropolar generators
• CPC Class Codes: H02K 19/36 Structural association of synchronous generators with auxiliary electric devices influencing the characteristic of the generator or controlling the generator, e.g. with impedances or switches
• CPC Class Codes: H02K 21/044 Rotor of the claw pole type
• CPC Class Codes: H02K 2203/09 Machines characterised by wiring elements other than wires, e.g. bus rings, for connecting the winding terminations
• CPC Class Codes: H02K 3/02 Windings characterised by the conductor material
• CPC Class Codes: H02K 3/12 arranged in slots
• CPC Class Codes: H02K 3/18 Windings for salient poles
• CPC Class Codes: H02K 3/24 with channels or ducts for cooling medium between the conductors
• CPC Class Codes: H02K 3/28 Layout of windings or of connections between windings windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32
• CPC Class Codes: H02K 3/34 between conductors or between conductor and core, e.g. slot insulation
• CPC Class Codes: H02K 3/44 Protection against moisture or chemical attack; Windings specially adapted for operation in liquid or gas
• CPC Class Codes: H02K 3/493 magnetic
• CPC Class Codes: H02K 3/505 for large machine windings, e.g. bar windings H02K3/51 takes precedence
• CPC Class Codes: H02K 3/528 of the claw-pole type
• CPC Class Codes: H02K 5/207 with openings in the casing specially adapted for ambient air
• CPC Class Codes: H02K 9/06 with fans or impellers driven by the machine shaft

Abstract

The present invention provides a compact, efficient and noiseless alternator for an automotive vehicle which employs a double-layer coil arrangement in a slot for eliminating coil end interference as well as improving the space factor. An automotive alternator comprises a Lundel-type core rotor with 16 poles, and a stator with toothed portions of 96 poles spaced by slots. U-shaped conductor segments are installed in the slots. One portion of the conductor is accommodated in an outer layer portion of a predetermined slot, while the other portion is accommodated in an inner layer portion of a slot phase shifted by an electric angle of 180°. In this manner, all of the slots are separated into the inner and outer layers to accommodate a plurality of conductor segments. These conductor segments are connected only at one side of the stator to form a total of twelve wavy winding coils. These twelve wavy winding coils are divided into three groups each consisting of a serial connection of four wavy windings to constitute one phase of a three-phase stator coil.

Claims

1. An alternator for an automotive vehicle, comprising:

a field rotor with N and S poles formed alternately in a circumferential direction, a stator including a stator core disposed in a confronting relationship with said rotor and a multi-phase stator winding associated with said stator core, and a frame supporting said rotor and said stator, wherein

said field rotor comprises a Lundel-type core having a plurality of hooked magnetic poles serving as said N and S poles,

said stator core comprises laminated cores formed with a plurality of slots extending across laminated plates,

said multi-phase stator winding comprises a plurality of conductor segments,

said plurality of conductor segments constitute at least one pair, and are inserted in said slots so as to constitute an inner layer and an outer layer arrayed in a depth direction of each slot, and said conductor segments are insulated from each other in each slot,

said plurality of conductor segments are partly disposed out of said slots so as to extend from an end face of said stator core and form a coil end having a predetermined connecting pattern according to which different layers disposed in different slots spaced at an interval corresponding to a N-and-S magnetic pole pitch of said field rotor are serially connected, thereby forming a coil end group chiefly repeating said connecting pattern at the end face of said stator core,

said plurality of conductor segments of said coil end are spatially separated from each other and extend in a direction intersectional with a flow direction of cooling air introduced in said frame, so that the cooling air can flow across said conductor segments of said coil end,

said plurality of slots comprises a plurality of slot groups, each slot group of one phase consisting of a plurality of slots spaced at predetermined intervals corresponding to the magnetic pole pitch of said field rotor, a first slot set being constituted by slot groups of multiple phases, and a second slot set being phase shifted from said first slot set by a predetermined electric angle,

said multi-phase stator winding comprises a first winding of said plurality of conductor segments accommodated in said slot groups included in said first slot set and a second winding of said plurality of conductor segments accommodated in said slot groups included in said second slot set, and said first winding of multi-phase and said second winding of multi-phase are combined so as to generate a summed-up output and are accommodated in said slot groups to be disposed a substantially equal distance in the radial direction from the center of the stator core.

2. The alternator for an automotive vehicle in accordance with claim 1, wherein said multi-phase stator winding has a winding end as an output terminal, and said stator and said rotor are cooperate to generate a voltage equal to or more than 15 volts from said winding end in an idling speed region of an engine which drives said rotor.

3. The alternator for an automotive vehicle in accordance with claim 1, wherein said first winding and said second winding are serially connected.

4. The alternator for an automotive vehicle in accordance with claim 3, wherein

said conductor segments accommodated in said first slot group are serially connected to form said first winding, and

said conductor segments accommodated in said second slot group are serially connected to form said second winding.

5. The alternator for an automotive vehicle in accordance with claim 1, wherein

said slots are disposed at regular intervals equivalent to an electric angle of 30°

,

some of said conductor segments accommodated in said plurality of slots constitute a first serial conductor group, said first serial conductor group serving as said first winding and comprising serially connected conductor segments accommodated in the slots of said first slot group,

conductor segments accommodated in the slots of said second slot group which are adjacent to said first slot group are serially connected to constitute a second serial conductor group, thereby serving as said second winding, and

said first serial conductor group and said second serial conductor group are connected in series to constitute a three-phase winding having a winding end connected to a rectifier.

6. The alternator for an automotive vehicle in accordance with claim 1, wherein

a first rectifier rectifies an AC output of said first winding,

a second rectifier rectifies an AC output of said second winding, and

a rectified output of said first rectifier and a rectified output of said second rectifier are summed up.

7. The alternator for an automotive vehicle in accordance with claim 6, wherein

said conductor segments accommodated in said first slot group are serially connected to form said first winding, and

said conductor segments accommodated in said second slot group are serially connected to form said second winding.

8. The alternator for an automotive vehicle in accordance with claim 1, wherein

two rectifiers are provided,

said slots are disposed at regular intervals equivalent to an electric angle of 30°

,

some of said conductor segments accommodated in said plurality of slots constitute a first serial conductor group, said first serial conductor group serves as said first winding and comprises serially connected conductor segments accommodated in the slots of said first slot group,

conductor segments accommodated in the slots of said second slot group which are adjacent to said first slot group are serially connected to constitute a second serial conductor group, thereby serving as said second winding, and

said first serial conductor group and said second serial conductor group independently constitute three-phase windings, each having a winding end connected to a corresponding rectifier.

9. The alternator for an automotive vehicle in accordance with claim 1, wherein

said Lundel-type core is defined by the following relationship

10. The alternator for an automotive vehicle in accordance with claim 1, wherein said plurality of conductor segments accommodated in a same slot are disposed exclusively in a depth direction of said same slot.

11. The alternator for an automotive vehicle in accordance with claim 1, wherein all of the conductor segments insulated in said slots are spatially separated at the coil end formed at an axial end portion of said stator core.

12. The alternator for an automotive vehicle in accordance with claim 1, wherein toothed core ends are positioned at both sides of at least one of said slots, and at least part of said toothed core is plastically deformed to form an opening of said at least one slot having a width narrower than a distance between inner walls of said at least one slot, said opening of said at least one slot being provided at an inner peripheral side of said slot.

13. The alternator for an automotive vehicle in accordance with claim 1, wherein each said conductor segment is formed into a rectangular shape fitting the configuration of a corresponding slot at a portion inserted in said corresponding slot.

14. The alternator for an automotive vehicle in accordance with claim 13, wherein

said conductor segments are naked metallic members,

an electrical insulating material is interposed between said plurality of conductor segments inserted in one said slot as well as between said plurality of conductor segments and inner walls of one said slot for assuring electric insulation, and

said plurality of conductor segments are spatially separated at a portion outside one said slot.

15. The alternator for an automotive vehicle in accordance with claim 1, wherein an overall axial length of said stator comprising said stator core and conductor segments accommodated in said slots is equal to or shorter than an overall axial length of said field rotor.

16. The alternator for an automotive vehicle in accordance with claim 1, wherein at least one said conductor segment is formed at least partly into a flat configuration at a portion outside said slots.

17. The alternator for an automotive vehicle in accordance with claim 1, wherein a magnet is interposed between magnetic poles of said field rotor so that said stator is exposed to a magnet flux in addition to a field flux.

18. The alternator for an automotive vehicle in accordance with claim 1, wherein said plurality of conductor segments disposed at said coil end receive said cooling air at substantially entire surfaces thereof.

19. The alternator for an automotive vehicle in accordance with claim 1, wherein said coil end group is formed at each axial end portion of said stator core, and two cooling air passages are formed in said frame so as to correspond to respective coil end groups.

20. The alternator for an automotive vehicle in accordance with claim 1, wherein a ventilating means is provided for causing a flow of cooling air in said frame.

21. The alternator for an automotive vehicle in accordance with claim 20, wherein said frame has a ventilation hole at a portion corresponding to said coil end group, so that the cooling air can flow across said conductor segments disposed at said coil end.

22. The alternator for an automotive vehicle in accordance with claim 20, wherein said ventilating means is provided at an axial end portion of said field rotor for causing a flow of cooling air directed in a centrifugal outer direction, so that the cooling air can flow across said conductor segments.

23. The alternator for an automotive vehicle in accordance with claim 22, wherein said ventilation means is provided at both axial end portions of said field rotor.

24. The alternator for an automotive vehicle in accordance with claim 23, wherein said ventilating means is a fan having a plurality of blades.

25. The alternator for an automotive vehicle in accordance with claim 23, wherein said Lundel-type core has a configuration corresponding to said plurality of hooked magnetic poles, so that said Lundel-type core is capable of serving as said ventilating means.

26. The alternator for an automotive vehicle in accordance with claim 25, wherein an axial end portion of said Lundel-type core is disposed in an adjacent and confronting relationship to an inner wall surface of said frame.

27. The alternator for an automotive vehicle in accordance with claim 22, wherein said frame has an inlet hole for said ventilating means, said inlet hole faces to an end of an installed pulley which drives said field rotor, and an outermost diameter of said inlet hole is smaller than an outermost diameter of said pulley.

28. The alternator for an automotive vehicle in accordance with claim 1, wherein said coil end is formed with a connecting pattern in which a first one of said conductor segments and a second one of said conductor segments are serially connected, said first conductor segment is disposed in a first of said slots as a predetermined layer, said second conductor segment is disposed in a second of said slots as a layer different from said first conductor segment, and said first and second slots are spaced at an interval corresponding to a N-and-S magnetic pole pitch of said field rotor.

29. The alternator for an automotive vehicle in accordance with claim 28, wherein

said coil end is formed by connecting an end portion of said first conductor segment extending from said first slot, and end portion of said second conductor segment from said second slot,

said first electric conductor and said second electric conductor are formed by separate conductor segments, and

the end portion of one of said first and second conductors has an angle and a length sufficient to span approximately a half of said magnetic pole pitch.

30. The alternator for an automotive vehicle in accordance with claim 29, wherein

each said conductor segment is an U-shaped segment having a turn portion formed by connecting two conductor segments continuously at one axial end portion of said stator core, and

an end portion of a first U-shaped segment serving as an end portion of said first conductor segment and an end portion of a second U-shaped segment serving as an end portion of said second conductor segment are connected according to said connecting pattern so as to form said coil end at another axial end portion of said stator core.

31. The alternator for an automotive vehicle in accordance with claim 29, wherein

each said conductor segment has two end portions protruding from both ends of a corresponding one of slots,

one coil end is formed at one end of said stator core by connecting one end portion of a first segment serving as an end portion of said first conductor segment and one end portion of a second segment serving as an end portion of said second conductor segment according to said connecting pattern, and

the other coil end is formed at the other end of said stator core by connecting the other end portion of said first segment serving as an end portion of said first conductor segment and the outer end portion of said second segment serving as an end portion of said second conductor segment according to said connecting pattern.

32. The alternator for an automotive vehicle in accordance with claim 31, wherein a sum of circumferential lengths of both end portions of one of said conductor segments corresponds to said magnetic pole pitch.

33. The alternator for an automotive vehicle in accordance with claim 31, wherein toothed core ends are positioned at both sides of at least one of said slots, and at least part of said toothed core end is plastically deformed to form an opening of said at least one slot having a width narrower than a distance between inner walls of said at least one slot, said opening of said at least one slot being provided at an inner peripheral side of said at least one slot.

34. The alternator for an automotive vehicle in accordance with claim 1, wherein a rectifier comprises rectifying elements, and part of said conductor segment is directly connected to an electrode of said rectifying element.

35. The alternator for an automotive vehicle in accordance with claim 34, wherein said conductor segment connected to the electrode of said rectifying element has an easily deformable portion between said stator and the electrode of said rectifying element.

36. The alternator for an automotive vehicle in accordance with claim 30, wherein a rectifier is disposed at a same side as the turn portion of said U-shaped segment and is connected to the winding end of said multi-phase stator winding.

37. The alternator for an automotive vehicle in accordance with claim 30, wherein a rectifier is disposed at a side opposed to the turn portion of said U-shaped segment and is connected to the winding end of said multi-phase stator winding.

38. The alternator for an automotive vehicle in accordance with claim 1, wherein said stator comprises extended wiring portions mutually short-circuited for constituting a neutral point.

39. The alternator for an automotive vehicle in accordance with claim 1, wherein said conductor segments constitute only one pair in each said slot.

40. The alternator for an automotive vehicle in accordance with claim 1, wherein said conductor segments constitute two or more pairs in each said slot.

41. The alternator for an automotive vehicle in accordance with claim 40, wherein

said plurality of conductor segments accommodated in said same slot are disposed exclusively in a depth direction,

said plurality of conductor segments are connected with other conductor segments at said coil end group to form a plurality of joint portions, and

said plurality of joint portions are arranged into multiple loops and mutually spaced in both a circumferential direction and a radial direction in said coil end group.

42. An alternator for an automotive vehicle, comprising:

a field rotor with N and S poles formed alternately in a circumferential direction, a stator disposed around said rotor in a confronting relationship, a frame supporting said rotor and said stator, and a rectifying AC power obtained from said stator in DC power, wherein

said stator comprises a laminated stator core formed with a plurality of slots, and a plurality of conductor segments are accommodated in said slots;

said conductor segments comprise a plurality of U-shaped segments, each having two straight portions accommodated in different slots spaced at an interval corresponding to a N-and-S magnetic pole pitch of said field rotor;

said plurality of U-shaped segments have turn portions each serving as a coil end protruding in an axial direction from one end face of said stator core, said turn portions being mutually spaced so as to form a first coil end group;

said plurality of slots comprises a plurality of slot groups, each slot group of one phase consisting of a plurality of slots spaced at predetermined intervals corresponding to the magnetic pole pitch of said field rotor, a first slot set being constituted by slot groups of multiple phases, and a second slot set being phase shifted from said first slot set by a predetermined electric angle,

a first winding comprises said plurality of conductor segments accommodated in said slot groups included in said first slot set and a second winding comprises said plurality of conductor segments accommodated in said slot groups included in said second slot set, and said first winding of multi-phase and said second winding of multi-phase are combined so as to generate a summed up output and are accommodated in said slot groups to be disposed a substantially equal distance in the radial direction from the center of the stator core,

said plurality of U-shaped segments have end portions protruding in an opposite axial direction from the other end face of said stator core, said end portions are connected according to a predetermined connecting pattern so as to constitute coil ends of a winding, and said coil ends are mutually spaced so as to form a second coil end group;

said field rotor comprises a Lundel-type core having a plurality of hooked magnetic poles serving as said N and S poles, and

two ventilation passages are provided at both axial ends of said field rotor, one ventilation passage extending in a radial direction so as to allow air to flow across said first coil end group, and the other ventilation passage extending in a radial direction so as to allow air to flow across said second coil end group.

43. The alternator for an automotive vehicle in accordance with claim 42, wherein said field rotor has an axial end portion equipped with a ventilation means for supplying air toward said coil end group.

44. The alternator for an automotive vehicle in accordance with claim 43, wherein said frame is provided with two ventilation holes serving as outlets of said ventilation means, one ventilation hole being provided adjacent to an outer peripheral side of said first coil end group, and the other ventilation hole being provided adjacent to an outer peripheral side of said second coil end group.

45. The alternator for an automotive vehicle in accordance with claim 42, wherein said U-shaped segments are electric conductors each having an elongated rectangular cross section, and a longitudinal direction of said cross section is disposed along a radial direction at said coil end.

46. The alternator for an automotive vehicle in accordance with claim 42, wherein

said electric conductors constitute a plurality of pairs of inner and outer layers, said straight portions of said electric conductors accommodated in said same slot being disposed exclusively in a depth direction of said slot,

a plurality of joint portions are formed by connecting said U-shaped segments, and

said plurality of joint portions are arranged into multiple loops and mutually spaced in both a circumferential direction and a radial direction in said second coil end group.

47. An alternator for an automotive vehicle, comprising:

a field rotor with N and S poles formed alternately in a circumferential direction, a stator including a stator core disposed in a confronting relationship with said rotor and a multi-phase stator winding associated with said stator core, and a frame supporting said rotor and said stator, wherein

said stator has a plurality of slots for accommodating said multi-phase stator winding,

said plurality of slots comprises a plurality of slot groups, each slot group of one phase consisting of a plurality of slots spaced at predetermined intervals corresponding to the magnetic pole pitch of said field rotor, a first slot set being constituted by slot groups of multiple phases, and a second slot set being phase shifted from said first slot set by a predetermined electric angle,

said multi-phase stator winding comprises a plurality of conductor segments,

said plurality of conductor segments constitute at least one pair, and are inserted in said slots so as to constitute an inner layer and an outer layer arranged in a depth direction of each said slot, and said conductor segments are insulated from each other in each said slot,

said plurality of conductor segments are partly disposed out of said slots external from an end face of said stator core and form a plurality of coil ends of serially connecting different layers disposed in different ones of said slots spaced at an interval corresponding to a magnetic pole pitch of said field,

said multi-phase stator winding comprises a first winding of said plurality of conductor segments accommodated in said slot groups included in said first slot set and a second winding of said plurality of conductor segments accommodated in said slot groups included in said second slot set, and said first winding of multi-phase and said second winding of multi-phase are combined so as to generate a summed-up output, and

said coil ends provide a substantially identical heat radiation surface for each winding of each slot group.

48. The alternator for an automotive vehicle in accordance with claim 47, wherein said plurality of conductor segments of said coil end extend in a direction intersectional with a flow direction of cooling air introduced in said frame, so that the cooling air can flow across said plurality of conductor segments of said coil end.

49. The alternator for an automotive vehicle in accordance with claim 47, wherein a plurality pair of said conductor segments are accommodated in each said slot and arrayed exclusively in a depth direction of each said slot,

said plurality of conductor segments are connected with other of said conductor segments at said coil ends to form a plurality of joint portions, and

said plurality of joint portions are arranged to form multiple loops and mutually spaced in both a circumferential direction and a radial direction in said coil ends.