U.S. patent application number 09/576899 was filed with the patent office on 2002-06-27 for a.c. generator for vehicle.
Invention is credited to Asao, Yoshihito, Fujita, Masahiko, Taji, Ryoichi.
Application Number | 20020079771 09/576899 |
Document ID | / |
Family ID | 18557709 |
Filed Date | 2002-06-27 |
United States Patent
Application |
20020079771 |
Kind Code |
A1 |
Taji, Ryoichi ; et
al. |
June 27, 2002 |
A.C. generator for vehicle
Abstract
Coil ends (19) of a stator coil (18) having a cross sectional
shape like a flat rectangular are constructed by first portions
extending from an outer layer of a pair of slots apart from
predetermined pitches in an axial direction and slanting in a
circumferential direction, second portions extending from an inner
layer of the other of the pair of the slots in the axial direction
and slanting in the circumferential direction, and third portions
positioned at ends of the coil ends (19) in the axial directions,
elongated in the radial direction and connected to ends of the
first and second portions in the axial direction, and in all of the
first, second and third portions, long sides (300) of the cross
sectional flat rectangular view of the stator coil (18) are
arranged to be substantially in parallel with an end surface of the
stator whereby the coil ends are lowered; and the coils are
arranged without a gap.
Inventors: |
Taji, Ryoichi; (Tokyo,
JP) ; Asao, Yoshihito; (Tokyo, JP) ; Fujita,
Masahiko; (Tokyo, JP) |
Correspondence
Address: |
Sughrue Mion Zinn MacPeak & Seas
2100 Pennsylvania Avenue NW
Washington
DC
20037
US
|
Family ID: |
18557709 |
Appl. No.: |
09/576899 |
Filed: |
May 23, 2000 |
Current U.S.
Class: |
310/179 ;
310/201 |
Current CPC
Class: |
H02K 3/24 20130101; H02K
3/12 20130101; H02K 9/06 20130101; H02K 11/046 20130101 |
Class at
Publication: |
310/179 ;
310/201 |
International
Class: |
H02K 001/00; H02K
003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2000 |
JP |
12-33196 |
Claims
What is claimed is:
1. An a.c. generator for vehicle comprising: a shaft accommodated
in a casing and one end of which is fixed to a pulley at one end; a
rotator fixed to the shaft; a fan located on an end surface of the
rotator in an axial direction; a stator assembled by a stator iron
core having slots and fixed to the casing, and a stator coil
accommodated in the slot; and a rectifier electrically connected to
the stator coil and located on a side opposite to the pulley,
wherein the coil ends of the stator coil having a cross sectional
shape like a flat rectangular are constructed by first portions
extending from an outer layer of a pair of slots apart from
predetermined pitches in an axial direction and slanting in a
circumferential direction, second portions extending from an inner
layer of the other of the pair of the slots in the axial direction
and slanting in the circumferential direction, and third portions
positioned at ends of the coil ends in the axial directions,
elongated in the radial direction and connected to ends of the
first and second portions in the axial direction, and in all of the
first, second and third portions, long sides in the cross sectional
flat rectangular view of the stator coil are arranged to be
substantially in parallel with an end surface of the stator.
2. The a.c. generator for vehicle according to claim 1, wherein the
third portions of the coil ends are bend in the axial direction
with a curvature, and the third portions are arranged substantially
without interposing gaps therebetween.
3. The a.c. generator for vehicle according to claim 1, wherein
connecting portions between the first portions and the third
portions and between the second portions and the third portions
escape each other by bending in the axial directions and the radius
direction so as to avoid interference between the coil ends.
4. The a.c. generator for vehicle according to claim 2, wherein
connecting portions between the first portions and the third
portions and between the second portions and the third portions
escape each other by bending in the axial directions and the radius
direction so as to avoid interference between the coil ends.
5. The a.c. generator for vehicle according to claim 1, wherein the
number of slots by each pole and each phase is two or more.
6. The a.c. generator for vehicle according to claim 2, wherein the
number of slots by each pole and each phase is two or more.
7. The a.c. generator for vehicle according to claim 1, wherein a
radius of the cross sectional flat rectangular of the stator coil
in the third portions of the coil ends is larger than the radius R
of portions of the slots for accommodating the stator coil.
8. The a.c. generator for vehicle according to claim 2, wherein a
radius of the cross sectional flat rectangular of the stator coil
in the third portions of the coil ends is larger than the radius R
of portions of the slots for accommodating the stator coil.
9. The a.c. generator for vehicle according to claim 1, wherein the
length of the rotator iron core in its axial direction is shorter
than the length of the stator in its axial direction.
10. The a.c. generator for vehicle according to claim 2, wherein
the length of the rotator iron core in its axial direction is
shorter than the length of the stator in its axial direction.
11. The a.c. generator for vehicle according to claim 1, wherein
lengths of the coil ends protruding from the stator iron core on
both sides of the shafts are the same on both of the sides.
12. The a.c. generator for vehicle according to claim 2, wherein
lengths of the coil ends protruding from the stator iron core on
both sides of the shafts are the same on both of the sides.
13. The a.c. generator for vehicle according to claim 1, wherein
the length of the coil ends protruding from the stator iron core on
a side of the rectifier is shorter than the length of the coil ends
protruding from the stator iron core on a side of the pulley.
14. The a.c. generator for vehicle, wherein the fan brings an air
from an inner diameter side to the outer diameter side of the coil
ends for cooling the coil ends.
15. The a.c. generator for vehicle according to claim 1, wherein
the fan is overlapped with the stator coil ends in the axial
direction.
16. The a.c. generator for vehicle according to claim 1, wherein
the stator coil is fabricated by connecting a plurality of segment
coils as electrical conductors, and the segment coils positioned in
different slots are connected after forming to bend in the
circumferential direction so that open ends of the segment coils
are connected.
17. The a.c. generator for vehicle according to claim 2, wherein
the stator coil is fabricated by connecting a plurality of segment
coils as electrical conductors, and the segment coils positioned in
different slots are connected after forming to bend in the
circumferential direction so that open ends of the segment coils
are connected.
18. The a.c. generator for vehicle according to claim 1, wherein
the rectifier is located on a side at which the coil ends are
turned.
19. The a.c. generator for vehicle according to claim 1, wherein a
varnish or a resin is located in the coil ends.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an a.c. generator for
vehicle, in particular a structure of a coil end of a stator of the
a.c. generator for vehicle.
[0003] 2. Discussion of Background
[0004] FIG. 18 is a perspective view of a coil end of a stator of
an a.c. generator for vehicle disclosed in Japanese Unexamined
Patent Publication JP-A-11-164504. In FIG. 18, a group of coils 32,
33, 34, 35, 36 inserted in an iron core 31 of the stator form
stationary blades, and a path for a cooling medium is formed
between coil ends. Because short sides of flat type stator winding
are directed toward a surface perpendicular to an axial direction
at the tops of the coil ends, although a ventilation trunk is
formed for an air flowing in a radial direction to demonstrate an
effect of the stationary blades, the height of the coil ends is
increased, and a pressure loss of the cooling medium is increased
at the tops of the coil ends, whereby a wind noise is increased,
and a flow rate by a fan is decreased to thereby increase a
temperature of heating element positioned on an upstream side.
Further, because the ventilation trunk in the radial direction,
namely a gap between coils, is formed by the stationary blades,
extraneous matters are apt to intrude into the ventilation trunk,
whereby cooling efficiency is spoiled; insulating coating is
damaged; and therefore quality is degraded.
[0005] The conventional a.c. generator for vehicle has problems
that the heights of the coil ends are increased; dimensions of the
stator are increased; the length of wiring is increased; a
resistance is increased; an output is decreased at time of
generating electricity; and the generator is excessively
heated.
[0006] Further, when the heights of the coil ends are increased,
there are problems that a leak inductance at the coil ends is
increased; an output is decreased; the length of the wire is
increased; a cost of the wire is increased; the coil ends prevent a
cooling air from flowing; and the heating element is insufficiently
cooled.
[0007] Further, because the flow path for the cooling medium is
formed between the coil ends, there are problems that the
extraneous matters are easily intrude into an inside of the
generator to cause failures; a flow of the cooling medium is made
turbulent; and a wind noise is increased.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to solve the
above-mentioned problems inherent in the conventional technique and
to provide an a.c. generator for vehicle, in which the heights of
the coil ends are lowered and coils are arranged without
interposing gaps.
[0009] According to a first aspect of the present invention, there
is provided an a.c. generator for vehicle comprising:
[0010] a shaft (5) accommodated in a casing (3) and being fixed to
a pulley (4) at one end;
[0011] a rotator (6) fixed to the shaft (5);
[0012] a fan (7a) located on an end surface of the rotator (6) in
an axial direction;
[0013] a stator (8) assembled by a stator iron core (17) having
slots and fixed to the casing (3), and a stator coil (18)
accommodated in the slot; and
[0014] a rectifier (12) electrically connected to the stator coil
(18) and located on a side opposite to the pulley (4),
[0015] wherein the coil ends (19) of the stator coil (18) having a
cross sectional shape like a flat rectangular are constructed by
first portions extending from an outer layer of a pair of slots
apart from predetermined pitches in an axial direction and slanting
in a circumferential direction, second portions extending from an
inner layer of the other of the pair of the slots in the axial
direction and slanting in the circumferential direction, and third
portions positioned at ends of the coil ends (19) in the axial
directions, elongated in the radial direction and connected to ends
of the first and second portions in the axial direction, and in all
of the first, second and third portions, long sides (300) in the
cross sectional flat rectangular view of the stator coil (18) are
arranged to be substantially in parallel with an end surface (17a)
of the stator.
[0016] According to a second aspect of the present invention, there
is provided the a.c. generator for vehicle,
[0017] wherein the third portions of the coil ends are bend in the
axial direction with a curvature, and
[0018] the third portions are arranged substantially without
interposing gaps therebetween.
[0019] According to a third aspect of the present invention, there
is provided the a.c. generator for vehicle,
[0020] wherein connecting portions between the first portions and
the third portions and between the second portions and the third
portions escape each other by bending in the axial directions and
the radius direction so as to avoid interference between the coil
ends.
[0021] According to a fourth aspect of the present invention, there
is provided the a.c. generator for vehicle,
[0022] wherein the number of slots by each pole and each phase is
two or more.
[0023] According to a fifth aspect of the present invention, there
is provided the a.c. generator for vehicle,
[0024] wherein a radius R of the cross sectional flat rectangular
of the stator coil in the third portions of the coil ends is larger
than the radius R of portions of the slots for accommodating the
stator coil.
[0025] According to a sixth aspect of the present invention, there
is provided the a.c. generator for vehicle,
[0026] wherein the length of the rotator iron core in its axial
direction is shorter than the length of the stator in its axial
direction.
[0027] According to a seventh aspect of the present invention,
there is provided the a.c. generator for vehicle,
[0028] wherein lengths of the coil ends protruding from the stator
iron core on both sides of the shafts are the same on both of the
sides.
[0029] According to an eighth aspect of the present invention,
there is provided the a.c. generator for vehicle,
[0030] wherein the length of the coil ends protruding from the
stator iron core on a side of the rectifier is shorter than the
length of the coil ends protruding from the stator iron core on a
side of the pulley.
[0031] According to a ninth aspect of the present invention, there
is provided the a.c. generator for vehicle,
[0032] wherein the fan brings an air from an inner diameter side to
the outer diameter side of the coil ends for cooling the coil
ends.
[0033] According to a tenth aspect of the present invention, there
is provided the a.c. generator for vehicle,
[0034] wherein the fan (7a) is overlapped with the stator coil ends
in the axial direction.
[0035] According to an eleventh aspect of the present invention,
there is provided the a.c. generator for vehicle,
[0036] wherein the stator coil is fabricated by connecting a
plurality of segment coils as electrical conductors, and
[0037] the segment coils positioned in different slots are
connected after forming to bend in the circumferential direction so
that open ends of the segment coils are connected.
[0038] According to a twelfth aspect of the present invention,
there is provided the a.c. generator for vehicle,
[0039] wherein the rectifier (12) is located on a side at which the
coil ends are turned.
[0040] According to a thirteenth aspect of the present invention,
there is provided the a.c. generator for vehicle,
[0041] wherein a varnish or a resin is located in the coil
ends.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] A more complete appreciation of the invention and many of
the attendant advantages thereof will be readily obtained as the
same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanied drawings, wherein:
[0043] FIG. 1 is a cross sectional view of an a.c. generator for
vehicle according to Embodiment 1 of the present invention;
[0044] FIG. 2 is a perspective view illustrating an inner coil
ends;
[0045] FIG. 3 is a plan view illustrating the inner coil ends;
[0046] FIG. 4 is a side view illustrating the inner coil ends;
[0047] FIG. 5 is a plan view illustrating the outer coil ends;
[0048] FIG. 6 is a side view illustrating the outer coil ends;
[0049] FIG. 7 is a cross sectional view illustrating a stator
coil;
[0050] FIG. 8 is a perspective view illustrating a rotator of a
claw pole type;
[0051] FIG. 9 is a perspective view illustrating coil ends
according to Embodiment 2 of the present invention;
[0052] FIG. 10 is a plan view illustrating the coil ends according
to Embodiment 2 of the present invention;
[0053] FIG. 11 is a side view illustrating coil ends according to
Embodiment 2 of the present invention;
[0054] FIG. 12a is a cross sectional view of a stator coil
according to Embodiment 3 of the present invention;
[0055] FIG. 12b is a cross sectional view of a stator coil
according to Embodiment 3 of the present invention;
[0056] FIG. 13 is a cross sectional view of a part of an a.c.
generator for vehicle according to Embodiment 4 of the present
invention;
[0057] FIG. 14 is a cross sectional view of a part of an a.c.
generator for vehicle according to Embodiment 6 of the present
invention;
[0058] FIG. 15 is a side view illustrating a stator coil according
to Embodiment 8 of the present invention;
[0059] FIG. 16 is a side view illustrating a stator coil according
to Embodiment 8 of the present invention;
[0060] FIG. 17 is a perspective view illustrating a stator
according to Embodiment 9 of the present invention; and
[0061] FIG. 18 is a perspective view illustrating conventional coil
ends.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0062] A detailed explanation will be given of preferred Embodiment
of the present invention in reference to FIG. 1 through 17 as
follows, wherein the same numerical references are used for the
same or similar portions and descriptions of these portions is
omitted.
[0063] Embodiment 1
[0064] FIG. 1 is a cross sectional view illustrating an a.c.
generator for vehicle according to Embodiment 1 of the present
invention. The a.c. generator includes a casing 3 constructed by
frames 1 and 2 made of aluminum; a shaft 5 located in the casing 3
and fixed to a pulley 4 at one end; a claw-type rotator 6 fixed to
the shaft 5; fans 7a, 7b respectively fixed to end surfaces of the
rotator 6; a stator iron core 17 fixed to the casing 3; a stator
coil 18 accommodated in slots of the stator iron core 17; a stator
8 constructed by the stator iron core 17 and the stator coil 18; a
slip ring 9 fixed to the other end of the shaft 5 for supplying an
electric current to the rotator 6; a pair of brushes 10 sliding on
the slip ring 9; a brush holder 11 for accommodating the brushes
10; a rectifier 12 electrically connected to the stator coil 18 for
commutating an a.c. current generated in the stator coil 18 to a
e.c. current; a heat sink 13 engaged with the brush holder 11; and
a regulator 14 engaged with the heat sink 13 for adjusting an a.c.
voltage generated in the stator coil 18.
[0065] The rotator 6 includes a rotator coil 15 for generating a
magnetic flux by an electric current and a pole core 16 served as a
magnetic pole by receiving the magnetic flux. The cooling fans 7a,
7b are respectively located on end surfaces of the pole core 16 in
its axial directions.
[0066] The stator 8 includes the stator iron core 17 through which
a rotating magnetic field generated by the rotator 6 passes, and
the stator coil 18 having a cross sectional shape like a flat
rectangular through which the a.c. output current passes by the
rotating magnetic field. The stator coil 18 has coil ends 19 on
both ends of the stator core 17 in its axial directions.
[0067] The rectifier 12 includes diodes 20 connected to the stator
coil 18 and a heat sink 21 for dissipating heat from the diodes
20.
[0068] The fan 7b rotates along rotation of the rotator 6, a
cooling air flows into the casing from an opening 100 of the casing
3, and the cooling air flows like an arrow 200 to cool the heat
sink 21 and the diodes 20. The cooling air further flows in an
outer direction of a radius of the fan 7b and is outward discharged
from an opening 101. A cooling air also flows into the casing 3
from an opening 102 by rotation of the fan 7b. The cooling air
flows like an arrow 201 and cools power transistors of the heat
sink 13 and the regulator 14. The cooling air flows in the outer
direction of the radius of the fan 7b by the fan 7b, and is outward
discharged from an opening 103.
[0069] FIGS. 2 through 6 illustrate the coil ends 19, wherein four
stator coils 18 are accommodated in a slot. FIG. 2 is a perspective
view illustrating the coil ends 19 of an inner stator coil 18a.
FIG. 3 is a plan view of the coil ends 19 viewed from an axial
direction. FIG. 4 is a side view of the coil ends viewed from the
radial direction. FIG. 5 is a plan view illustrating the coil ends
19 of an outer stator coil 18b. FIG. 6 is a side view of the coil
ends. The outer stator coil 18b is located so as to cover the inner
stator coil 18a. FIG. 7 is a cross sectional view of the stator
coil 18 having a long side 300 and a short side 301.
[0070] As illustrated in FIGS. 2 through 4, the coil ends 19
include a first portion extending from a third layer, i.e. an outer
layer, of a pair of slots apart by a predetermined pitch and
slanting in a circumferential direction, a second portion extending
from a second layer, i.e. an inner layer, of the other slot in the
axial direction and slanting in the circumferential direction, and
a third portion positioned at ends of the coil ends 19 in the axial
direction, extending substantially in a radial direction, and
connected to ends of the first and second portions in the axial
directions.
[0071] In all of the first, second and third portions of the coil
ends, the long sides 300 are arranged in parallel with an end
surface 17a of the stator and a surface including the short sides
301 is arranged in vertical with the end surface 17a of the stator,
namely only the long sides 300 are visible and the short sides 301
are invisible in FIG. 3, wherein there is no twisting portion in
coil ends, wherein twisting portions exist in the conventional
technique.
[0072] Further, in the third portions of the coil ends, a portion
105 extending in the circumferential and radial direction and bent
with a curvature in the axial direction as illustrated in FIG. 4.
The coil ends 19 have the same shape, and the third portions of the
coil ends 19 are arranged substantially without gaps in the
circumferential direction.
[0073] Therefore, the heights of the third portions are lowered,
and it becomes possible to arrange the stator coils 18 without
gaps.
[0074] Further, connecting portions between the first portions and
the third portions and between the second portions and the third
portions have a relief 105 bending in the axial and radial
direction so as to avoid interference between the coil ends 19.
[0075] Accordingly, because the heights of the third portions of
the coil ends are lowered, it is possible to make an entire a.c.
generator for vehicle small; an air flow resistance at the third
portions is decreased; cooling capability is improved; and a
temperature of a heating element is decreased. Further, a
resistance of the coils and a leak inductance from the coil ends
are reduced, whereby an output is improved. Further, because a
copper loss is decreased, efficiency is improved.
[0076] Further, because the heights of the coil ends is lowered, a
pressure loss of the cooling air is decreased. Unevenness of a
surface of the rotator becomes small, whereby an interference sound
between the coil ends and the cooling air can be decreased.
[0077] Further, because the amount of the copper, i.e. coil, at a
high unit price is decreased, a production cost can be reduced.
[0078] Further, because the third portions of the coil ends 19 are
arranged substantially without gaps, an extraneous matter is not
easily intrude from an outside into the third portions, whereby it
becomes possible to avoid damages to a coil insulating coating, an
insulating property is improved, and an interference sound between
the cooling air and the third portion can be canceled.
[0079] Further, because the rotator 6 is constructed so as to avoid
an interference between the coil ends, it becomes possible to lower
the heights of the coil ends, and a short caused by the
interference can be prevented to thereby enhance an insulating
property.
[0080] Further, the rotator 6 is a claw pole type as illustrated in
FIG. 8. Therefore, shoulders 22 can be used as a means for blowing
an air, whereby a cooling capability is further improved.
Meanwhile, the rotator 6 may be a salient type.
[0081] Embodiment 2
[0082] FIGS. 9 through 11 illustrate coil ends 19 according to
Embodiment 2 of the present invention, wherein two stator coils 18
are accommodated in a slot. FIG. 9 is a perspective view
illustrating the coil ends 19. FIG. 10 is a plan view of FIG. 9
viewed from an axial direction. FIG. 11 is a side view of FIG. 9
viewed from a radius direction.
[0083] As illustrated in FIGS. 9 through 11, the coil ends 19
include a first portion extending from a second layer of a pair of
slots apart by a predetermined pitch and slanting in a
circumferential direction, a second portion extending from an inner
layer of the other slot in the axial direction and slanting in a
circumferential direction, and a third portion positioned at ends
of the coil ends 19 in the axial direction and extending
substantially in the radius direction so as to be connected to ends
of the first and second portions in the axial direction.
[0084] In all of the first, second and the third portions of the
coil ends, the long side 300 is in parallel with an end surface 17a
of the stator, and a surface including short sides 301 is
perpendicular to the end surface 17a of the stator. In other words,
in FIG. 10, only the long side 300 can be observed and the short
sides 301 can be seldom observed. Not like the conventional
technique, there is no twisting portion at the coil ends.
[0085] Further, connecting portions between the first and third
portions and between the second and third portions of the coil ends
19 have a relief bending in the axial and radius direction so as to
avoid interference between the coil ends 19. Because of such a
structure of avoiding the interference between the coil ends, it is
possible to lower the heights of the coil ends, insulation is
enhanced by preventing a short caused by the interference, and the
stator coils 18 are arranged without any gap.
[0086] Embodiment 3
[0087] It is also possible to make a radius of shoulders in a cross
sectional flat rectangular shape of third portions of coil ends 19,
illustrated in FIG. 12a, larger than a radius of a cross sectional
shape of portions for accommodating stator coils 18 in a slot of a
stator iron core illustrated in FIG. 12b. Because the radius of the
shoulders of the coil ends 19 is increased at where the coil ends
are in contact with each other, coils are not in contact at edges;
it is possible to prevent a coating from peeling off; and much
wiring can be efficiently arranged in the slots.
[0088] Further, it is possible to construct such that at least one
of the coil ends 19 of the stator coil 18 is arranged on a
downstream side next to a fan 7 as a means for blowing an air.
[0089] By arranging the coil ends 19 on the downstream side next to
the means for blowing an air, it is possible to improve a
capability of cooling.
[0090] Further, at least one of frames 1 and 2 may be formed to
have a plurality of openings on an outer peripheral side of the
coil ends 19. Because there are the plurality of openings on the
outer peripheral side of the coil ends 19, it is possible to
improve heat dissipation to the outer peripheral side. Further, the
stator coils 18 are arranged without a gap therebetween, whereby it
is possible to prevent an extraneous matter from intruding from the
openings to the coil ends 19.
[0091] Further, it may be construct such that the plurality of
openings are formed in a range other than a portion 106 in FIG. 1,
at which cores of the coil ends 19 protrude.
[0092] Although an excessive air flow and an extraneous matter from
an outside are apt to intrude into the portion where the cores
protrude because spaces between the stator coils 18 exists, it is
possible to prevent such troubles by locating the openings in a
range other than the portion.
[0093] Embodiment 4
[0094] As illustrated in FIG. 1, because the fans 7a, 7b rotating
along with the rotator 6 are provided as a means for blowing an
air, it is possible to certainly cool a generator at a low cost.
Further, the fan 7 may be located on at least one end of the
rotator 6, whereby coil ends 19 can be cooled by sending an air
from an inner peripheral side to an outer peripheral side.
[0095] Because the means for blowing air is the fan 7, a speed of
the air is maximum at tip ends of the coil ends 19 positioned on a
downstream side. Since an air resistance in the third portion
extremely deteriorates a capability of the fan, the coil ends 19
are preferable. Further, the coil ends 19 receive the cooling air
from the inner peripheral side through the coil ends 19 to a frame
opening positioned outside the coil ends 19 by the fan 7 located at
the end of the rotator 6, whereby a cooling effect is high.
[0096] Further, as illustrated in FIG. 13, the fan 7 may be
overlapped with the coil ends 19 of the stator in an axial
direction by a distance 107.
[0097] Because the fan 7 is overlapped with the coil ends 19 in the
axial direction, a cooling effect is high.
[0098] Further, it may be constructed such that a distance 108
between an inner peripheral surface of the coil ends 19 and an
outer diameter of the fan 7 in FIG. 13 is substantially equal along
a circumferential direction. In this case, an interference sound
generated between fan blades and the coil ends is equalized to
reduce a wind noise.
[0099] Embodiment 5
[0100] It is possible to make the length of a stator 8 in an axial
direction shorter than the length of a rotator iron core in its
axial direction. Because stator coils 18 are not spaced, coil ends
19 can be made low and shorter than the rotator 6 in the axial
direction, a resistance against a cooling air is reduced; a
capability of cooling inner components such as a rectifier 12 and a
regulator 14 as heating elements is improved; and the generator can
be miniaturized.
[0101] Embodiment 6
[0102] As illustrated in FIG. 14, the length of coil ends 19
protruding on both sides of a shaft from a stator iron core in an
axial direction may be substantially the same as illustrated in
numerical references 109 and 110 of FIG. 14. In this case, air
resistances on both ends of a core can be made the same, and a
stator 8 is uniformly cooled.
[0103] Meanwhile, a length 109 on a side of the heating element may
be shorter than a length 110. In this case, the air resistance on
the side of the heating element can be further reduced.
[0104] Embodiment 7
[0105] The number of slots by each pole and each phase may be two
or more. In this case, the number of slots for accommodating coils
is large, whereby it is possible to arrange coil ends 19 of the
coils without gaps.
[0106] Embodiment 8
[0107] It is also possible to construct a stator coil 18 by
connecting a plurality of electrical conductors, i.e. segment coils
23, as illustrated in FIG. 15. In this case, shapes of coil ends 19
become uniform and the coils can be easily arranged without gaps
therebetween.
[0108] As illustrated in FIG. 16, it is also possible to construct
such that the electric conductors are U-like shape segment coils
24, the U-like shape segment coils 24 are respectively positioned
in different slots, and open ends 24a of the U-like shape segment
coils 24 are connected after bending the segment coils 24 in a
circumferential direction.
[0109] By inserting the segment coils 24 into a core in an axial
direction and connecting these, it is possible to wind the segment
coils without intervals, and a production becomes easy.
[0110] In this case, coil ends 19 on a connecting side of the
U-like segment coils 24 and coil ends 19 on a bending side of the
U-like shape segment coils 24 are oppositely arranged. Third
portions do not appear on the connecting side, and the coils can be
easily formed in use of the bending side of the segment coils as
the third portions.
[0111] Further, it is possible to locate a fan 7 on an end of a
rotator 6 on the bending side of the stator coil ends 19. In this
case, because the fan 7 is located on the end of the rotator 6 on
the bending side having a shorter length of the stator coil ends 19
in the axial direction, an air resistance on a discharge side of
the fan 7 is decreased, and an air flow rate is increased, whereby
a temperature is reduced.
[0112] Further, it is possible to locate a rectifier 12 on the
bending side. Because the rectifier 12, being a heating element, is
arranged on the bending side having a shorter length of the stator
coil ends 19 in the axial direction, an air resistance on the
discharge side of the fan 7 is small, and an air flow rate passing
through the rectifier 12 is increased, whereby a temperature of the
rectifier 12 is reduced.
[0113] Further, the number of blades of a fan 7b on the bending
side may be increased in comparison with the number of blades of a
fan 7a on a pulley side. In this case, it becomes possible to
enhance a capability of flowing a cooling air by the fan 7b on a
rectifier side.
[0114] Embodiment 9
[0115] By coating a varnish in at least coil ends 19 of a stator
coil 18, it is possible to locate a varnish layer between the coil
ends 19. In this case, small gaps between the coil ends 19 are
clogged by the varnish, whereby insulation and an adhesive force
are further improved.
[0116] Further, a resin layer may be located in at least gaps
between the coil ends 19 of the stator coil 18 by embedding a
resin. In this case, small gaps between the coil ends 19 are
further clogged by the resin, whereby insulation and an adhesive
force are further improved.
[0117] Further, as illustrated in FIG. 17, an entire surface of the
coil ends 19 may be evenly covered by a resin. In FIG. 17,
numerical reference 25 designates the stator core, and numerical
reference 26 designates the resin. In this case, the surface of the
coil ends 19 can be made flat, whereby a resistance against a
cooling air and an interference sound are further reduced.
[0118] The first advantage of the a.c. generator for vehicle
according to the present invention is that an entire size of the
generator can be small; the air resistance at the third portions
are decreased; and the capability of cooling is improved, whereby
the temperature of the heat element can be reduced. Further, the
resistance of the coil and the leak inductance of the coil ends are
reduced, whereby an output power is improved and the copper loss is
decreased to improve the efficiency.
[0119] Further, the interference sound between the third portions
and the cooling air can be reduced, and the cost can be
decreased.
[0120] The second advantage of the a.c. generator for vehicle
according to the present invention is that the extraneous matter
does not easily intrude from the outside.
[0121] The third advantage of the a.c. generator for vehicle
according to the present invention is that the short caused by the
interference can be prevented, and the insulation is improved.
[0122] The fourth advantage of the a.c. generator for vehicle
according to the present invention is that the coil ends of the
coils can be easily arranged without gaps.
[0123] According to the fifth advantage of the a.c. generator for
vehicle according to the present invention is that the coating of
the coils at the coil ends can be prevented from peeling off.
[0124] The sixth advantage of the a.c. generator for vehicle
according to the present invention is that the air resistance is
decreased to improve the capability of cooling the heat
element.
[0125] The seventh advantage of the a.c. generator for vehicle
according to the present invention is that the air resistances on
both ends of the core can be made the same to uniformly cool the
stator.
[0126] The eighth advantage of the a.c. generator for vehicle
according to the present invention is that the air resistance on
the heat element side can be further reduced.
[0127] The ninth advantage of the a.c. generator for vehicle
according to the present invention is that the cooling efficiency
can be improved.
[0128] The tenth advantage of the a.c. generator for vehicle
according to the present invention is that the cooling efficiency
is improved.
[0129] The eleventh advantage of the a.c. generator for vehicle
according to the present invention is that the coils can be wound
without gaps and easily produced.
[0130] The twelfth advantage of the a.c. generator for vehicle
according to the present invention is that the temperature of the
rectifier can be reduced.
[0131] The thirteenth advantage of the a.c. generator for vehicle
according to the present invention is that the coil ends can be
formed with further smaller gaps.
[0132] Obviously, numerous modifications and variations of the
present invention are possible in light of the above teachings. It
is therefore to be understood that within the scope of the appended
claims, the invention may be practiced otherwise than as
specifically described herein.
[0133] The entire disclosure of Japanese Patent Application No.
12-33196 filed on Feb. 10, 2000 including specification, claims,
drawings and summary are incorporated herein by reference in its
entirety.
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