U.S. patent application number 12/801706 was filed with the patent office on 2010-10-14 for stator of electric rotating machine.
This patent application is currently assigned to NIPPON SOKEN, INC.. Invention is credited to Hirofumi Kinjo, Shinji Kouda, Hirohito Matsui, Katsuhiko Oka, Sadahisa Onimaru.
Application Number | 20100257722 12/801706 |
Document ID | / |
Family ID | 41200525 |
Filed Date | 2010-10-14 |
United States Patent
Application |
20100257722 |
Kind Code |
A1 |
Onimaru; Sadahisa ; et
al. |
October 14, 2010 |
STATOR OF ELECTRIC ROTATING MACHINE
Abstract
A method of manufacturing an electric rotating machine having a
stator that includes a stator core having slots formed at an inner
periphery thereof, and a stator winding constituted by conductive
wires wound on the slots. The stator winding includes in-slot
portions accommodated in the slots and turn portions each
connecting each adjacent two of the in-slot portions outside the
slots. The stator core includes a core member having at least three
tooth portions extending in a radial direction of the stator core
and a core back portion integrally connecting the tooth portions at
a radially end side thereof. The core member is configured such
that each of the first tooth portions folded toward the core back
portion is capable of unfolding to extend between a corresponding
adjacent two of the in-slot portions when the core member is at a
predetermined axial position with respect to the stator
winding.
Inventors: |
Onimaru; Sadahisa;
(Chiryu-shi, JP) ; Matsui; Hirohito; (Okazaki-shi,
JP) ; Kinjo; Hirofumi; (Oobu-shi, JP) ; Oka;
Katsuhiko; (Kariya-shi, JP) ; Kouda; Shinji;
(Kariya-shi, JP) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Assignee: |
NIPPON SOKEN, INC.
Nishio-city
JP
DENSO CORPORATION
Kariya-city
JP
|
Family ID: |
41200525 |
Appl. No.: |
12/801706 |
Filed: |
June 22, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12423876 |
Apr 15, 2009 |
|
|
|
12801706 |
|
|
|
|
Current U.S.
Class: |
29/596 |
Current CPC
Class: |
H02K 15/024 20130101;
H02K 1/16 20130101; Y10T 29/49009 20150115 |
Class at
Publication: |
29/596 |
International
Class: |
H02K 15/06 20060101
H02K015/06 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 18, 2008 |
JP |
2008-109549 |
Claims
1. A method of manufacturing a stator of an electric rotating
machine, said stator comprising a stator core and a stator winding,
the method comprising: providing a plurality of core members for
forming at least a portion of the stator core, each said core
member having at least three first tooth portions to extend in a
radial direction of said stator core and a core back portion
integrally connecting said first tooth portions at a radially outer
end side thereof, said first tooth portions defining slots
therebetween at an inner periphery of the stator core along a
circumferential direction thereof, each of said first tooth
portions being selectively foldable or bendable to extend at least
in part in a direction that is at an angle to said radial
direction; providing a stator winding constituted by wound
conductive wires, said stator winding including in-slot portions
adapted to be accommodated in said slots of the stator core and
turn portions each connecting each adjacent two of said in-slot
portions outside of said slots; folding or bending the tooth
portions of at least one of the core members thereby to form a
hollow portion having a diameter that accommodates the stator
winding at an axial center portion of the core member; in the state
of the tooth portions being folded or bent, inserting the stator
winding into the hollow portion, and sliding the core member in the
axial direction thereof; and when the core member reaches a
predetermined axial position with respect to the stator winding,
unfolding the tooth portions so that the tooth portions extend
radially inwardly to assume substantially their original shape,
whereby each of the tooth portions radially penetrates between the
adjacent in-slot portions of the stator winding and each of the
in-slot portions is accommodated between each adjacent two of the
tooth portions.
2. The method according to claim 1, wherein each of the core
members is successively assembled to the stator winding by folding
or bending the tooth portions thereof and receiving the stator
winding in the hollow portion defined thereby.
3. The method according to claim 1, wherein said tooth portions are
resiliently flexible so that they resiliently flex to accommodate
said stator winding, and they self-unfold to penetrate through the
stator winding.
4. The method according to claim 1, wherein said providing a
plurality of core members comprises providing core members having a
ring-like shape core back portion.
5. The method according to claim 1, wherein said providing a
plurality of core members comprises providing core members made of
an amorphous metal plate.
6. The method according to claim 1, wherein said providing a stator
winding comprises providing a stator winding having a shape of a
cylinder having open ends, and said core members being slid along
said stator winding from a side of one of said open ends to said
predetermined axial position to be assembled to said stator
winding.
7. The method according to claim 1, wherein said conductive wire
has a rectangular cross-sectional shape.
8. The method according to claim 1, wherein said conductive wire is
wound over an entire circumferential length of said stator
core.
9. The method according to claim 1, wherein said conductive wire
includes a conductor and an insulating film covering an outer
surface of said conductor, said insulating film having a thickness
from 100-200 .mu.m.
10. The method according to claim 9, wherein said insulating film
is constituted by an inner layer and an outer layer, a glass
transition temperature of said outer layer being lower than that of
said inner layer.
11. The method according to claim 9, wherein said insulating film
is coated with a fusion member.
12. The method according to claim 9, wherein said conductor of said
conductive wire is made of aluminum.
13. The method according to claim 2, further comprising: providing
divided core members for forming at least a portion of the stator
core, each of said divided core members being made of metal plate,
and having at least two second tooth portions extending in said
radial direction, and a core back portion integrally connecting
said second tooth portions at a radially outer end side
thereof.
14. The method according to claim 13, further comprising:
assembling the divided core members to both axial ends of the
previously assembled core members, the divided core members being
assembled in a direction from radially outside of the stator
winding to the axial center of the stator winding, thereby to fill
gaps between axial end surfaces of the assembled core members and
end surfaces of the stator winding.
15. The method according to claim 14, further comprising: joining
band-like fittings to the divided core members assembled to the
laminated body of the core members to complete the stator core.
16. A method of manufacturing an electric rotating machine
comprising a stator and a rotor having magnet poles formed such
that N poles and S poles alternate along a circumferential
direction of said rotor so as to face an inner or outer periphery
of said stator, said stator comprising a stator core and a stator
winding, the method comprising: providing a plurality of core
members for forming at least a portion of the stator core, each
said core member having at least three first tooth portions to
extend in a radial direction of said stator core and a core back
portion integrally connecting said first tooth portions at a
radially outer end side thereof, said first tooth portions defining
slots therebetween at an inner periphery of the stator core along a
circumferential direction thereof, each of said first tooth
portions being selectively foldable or bendable to extend at least
in part in a direction that is at an angle to said radial
direction; providing a stator winding constituted by wound
conductive wires, said stator winding including in-slot portions
adapted to be accommodated in said slots of the stator core and
turn portions each connecting each adjacent two of said in-slot
portions outside of said slots; folding or bending the tooth
portions of at least one of the core members thereby to form a
hollow portion having a diameter that accommodates the stator
winding at an axial center portion of the core member; in the state
of the tooth portions being folded or bent, inserting the stator
winding into the hollow portion, and sliding the core member in the
axial direction thereof; and when the core member reaches a
predetermined axial position with respect to the stator winding,
unfolding the tooth portions so that the tooth portions extend
radially inwardly to assume substantially their original shape,
whereby each of the tooth portions radially penetrates between the
adjacent in-slot portions of the stator winding and each of the
in-slot portions.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Division of application Ser. No.
12/423,876, filed Apr. 15, 2009, which claims priority from and is
based on Japanese Patent Application No. 2008-109549 filed on Apr.
18, 2008, the contents of each of which are hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a stator of an electric
rotating machine, and an electric rotating machine having the
stator.
[0004] 2. Description of Related Art
[0005] In recent years, there is a growing need of electric
rotating machines usable as electric motors or generators which are
compact in size and of high quality.
[0006] For example, an electric rotating machine mounted on a
vehicle is required to generate more output power because of an
increase of vehicle loads, although the space assigned to mount the
electric rotating machine in an engine compartment is becoming
smaller.
[0007] As described, for example, in Japanese Patent No. 3604326,
there is known a compact and high-output electric rotating machine
having a structure in which the resistance of phase windings
thereof is small, the lamination factor of electric conductors
accommodated in the magnetic circuit of a stator thereof is large,
and the turn portions of the phase windings are in proper alignment
and wound densily.
[0008] This patent document describes, as an assembling method of
the stator, a step of preparing a stator winding of a predetermined
shape by winding pillar-conductors in the circumferential direction
a plurality of times so as to be laminated in the slot direction
(in the radial direction), a step of disposing a plurality of
divided cores in a ring around the outer periphery of the stator
winding in a state of being overlapped at their lap portions, a
step of moving the divided cores radially inwardly so that they are
inserted into the stator winding, and a step of fixing the divided
cores to one another.
[0009] However, the stator of an electric rotating machine of the
type in which its stator core is constituted by a plurality of
divided cores has a problem in that it is difficult for the
electric rotating machine to output a sufficiently large power,
because the divided portions (surfaces of the divided cores) have a
magnetic resistance.
[0010] Although the above patent discloses reducing the magnetic
resistance by the provision of the lap portions, the effect is
restrictive.
In addition, there is another problem that an eddy current occurs
in each lap portion, causing iron loss (core loss) to increase.
SUMMARY OF THE INVENTION
[0011] The present invention provides a stator of an electric
rotating machine comprising: [0012] a stator core having slots
formed at an inner periphery thereof along a circumferential
direction thereof; and [0013] a stator winding constituted by
conductive wires wound on the slots [0014] the stator winding
including in-slot portions accommodated in the slots and turn
portions each connecting each adjacent two of the in-slot portions
outside of the slots, [0015] the stator core including a core
member having at least three first tooth portions extending in a
radial direction of the stator core and a core back portion
integrally connecting the first tooth portions at a radially end
side thereof, [0016] the core member being configured such that
each of the first tooth portions folded toward the core back
portion is capable of unfolding to extend between a corresponding
adjacent two of the in-slot portions when the core member is at a
predetermined axial position with respect to the stator
winding.
[0017] According to the present invention, there is provided a
compact and high-output electric rotating machine including a
stator having less magnetic resistance in a stator core
thereof.
[0018] Other advantages and features of the invention will become
apparent from the following description including the drawings and
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the accompanying drawings:
[0020] FIG. 1 is a diagram showing a structure of an electric
rotating machine according to a first embodiment of the
invention;
[0021] FIG. 2 is a diagram showing a core member constituting a
stator of the electric rotating machine according to the first
embodiment of the invention;
[0022] FIG. 3 is a diagram of divided core members constituting the
stator of the electric rotating machine according to the first
embodiment of the invention;
[0023] FIG. 4 is a diagram showing the divided core members
disposed in a ring;
[0024] FIG. 5 is an outline view of the stator of the electric
rotating machine according to the first embodiment of the
invention;
[0025] FIGS. 6A and 6B are diagrams showing cross sections of phase
windings constituting a stator winding of the electric rotating
machine according to the first embodiment of the invention;
[0026] FIG. 7 is a diagram showing electrical connection of the
phase windings of a stator winding of the electric rotating machine
according to the first embodiment of the invention;
[0027] FIG. 8 is a perspective view of the stator winding of the
electric rotating machine according to the first embodiment of the
invention;
[0028] FIG. 9 is an exploded view of the stator winding of the
electric rotating machine according to the first embodiment of the
invention;
[0029] FIG. 10 is a diagram for explaining a method of assembling
the stator of the electric rotating machine according to the first
embodiment of the invention;
[0030] FIG. 11 is a diagram for explaining a method of assembling
the stator of the electric rotating machine according to the first
embodiment of the invention;
[0031] FIG. 12 is a diagram for explaining a method of assembling a
stator of the electric rotating machine according to a second
embodiment of the invention;
[0032] FIG. 13 is an outline view of the stator of the electric
rotating machine according to the second embodiment of the
invention;
[0033] FIG. 14 is an outline view of the stator of the electric
rotating machine according to a third embodiment of the
invention;
[0034] FIG. 15 is a diagram for explaining a method of assembling a
stator of an electric rotating machine according to a fourth
embodiment of the invention;
[0035] FIG. 16 is a partially enlarged view of a core member of a
stator of an electric rotating machine according to a fifth
embodiment of the invention; and
[0036] FIG. 17 is a diagram showing a structure of a core member of
a stator of an electric rotating machine according to a sixth
embodiment of the invention.
PREFERRED EMBODIMENTS OF THE INVENTION
First Embodiment
[0037] Fig. is a diagram showing a structure of an electric
rotating machine 1 according to a first embodiment of the
invention. As shown in this figure, the electric rotating machine 1
includes a housing 10 constituted by a pair housing members 100 and
101 each having a bottomed tubular shape and joined to each other
at their opening portions, a rotor 2 fixed to a rotating shaft 20
rotatably supported by the housing 10 through bearings 110 and 111,
and a stator 3 fixed to the housing 10 so as to surround the rotor
2 inside the housing 10.
[0038] The rotor 2 is provided with a plurality of magnetic poles
(S poles and N poles) formed in the outer periphery of the rotor 2
facing the inner periphery of the stator 3, such that different
poles alternate in the circumferential direction of the rotor
2.
[0039] The stator 3 includes a stator core 30, and a three-phase
stator winding 4 constituted by a plurality of phase windings.
[0040] The stator core 30 has a shape of a circular ring formed
with slots 31 at its inner periphery. The depth direction of each
slot 31 coincides with the radial direction of the stator core
30.
[0041] The stator core 30 includes core members 32. As shown in
FIG. 2, the core member 32 is constituted by a plurality of tooth
portions 320 arranged in the circumferential direction, and a core
back portion 321 having a nearly circular ring shape disposed
radially outward of the tooth portions 320 and being integral with
the tooth portions 320. The core member 32 is formed by shaping an
amorphous metal plate 25 .mu.m thick (Optronics Co., Ltd. make,
product name: METGLAS2605TCA). Since the core member 32 is made of
a thin metal plate, it is flexible.
[0042] The stator core 30 further includes divided core members 33.
As shown in FIG. 3 the divided core member 33 includes two tooth
portions 330 and a core back portion 331 of a roughly arc shape
disposed radially outward of the tooth portions 330 and being
integral with the tooth portions 330. The divided core member 33 is
formed by shaping an electromagnetic steel plate of 0.35 mm thick.
Since the divided core member 33 is made of a relatively thick
metal plate, it does not have flexibility. FIG. 4 is a diagram
showing the divided core members 33 arranged in a circle.
[0043] As shown in FIG. 5, the stator core 30 is formed by
laminating the core members 32 and the divided core members 33. The
core members 32 and the divided core members 33 are fixed to one
another by fittings 34 made of stainless steel.
[0044] The stator winding 4 is constituted by a plurality of
windings 40 wound together in a given way. As shown in FIG. 6A,
each of the windings 40 includes a conductor 41 made of copper or
aluminum and an insulating film 42 constituted by an inner layer
420 and an outer layer covering the outer surface of the conductor
41. The thickness of the insulating film 42 is between 100 .mu.m
and 200 .mu.m. Since the insulating film 42 is sufficiently thick,
it is not necessary to interpose insulating paper or the like
between each of the wirings 40 for insulation therebetween.
However, insulating paper or the like may be interposed between
each of the wirings 40.
[0045] The outer layer 421 is made of insulating material such as
nylon, and the inner layer 420 is made of insulating material
having a glass transition temperature higher than that of the outer
layer 421 such as thermoplastic resin or polyamideimide.
Accordingly, since the outer layer 421 crystallizes at an earlier
time than the inner layer 420 when the electric rotating machine 1
generates heat, the surface hardness of the winding 40 increases,
and accordingly, the winding 40 is difficult to scratch.
[0046] As shown in FIG. 6B, the outer surface of the insulating
film 42 of the winding 40 may be coated with a fusion member 48
made of fusion material such as epoxy resin. The fusion member 43
melts at an earlier time than the insulating film 42 when the
electric rotating machine 1 generates heat, and accordingly,
windings 40 accommodated in the same slot 31 heat-adhere to one
another through their fusion members 43. As a result, since the
windings 40 accommodated in the same slot 31 become integrated and
rigid, the mechanical strength of the windings 40 increases.
[0047] In this embodiment, as shown in FIG. 7, the stator winding 4
is constituted by two sets of three-phase windings (windings U1,
U2, V1, V2, W1 and W2).
[0048] As shown in FIG. 8, the stator winding 4 is constituted by
the windings 40 wound together in a predetermined shape. Each of
the windings 40 is wave-wound along the circumferential direction
on the side of the inner periphery of the stator core 30. Each of
the windings 40 includes in-slot portions 44 of a linear shape
accommodated in the slots 31, and turn portions 45 connecting the
adjacent in-slot portions 44 to each other. The in-slot portions 44
of the same winding 40 are accommodated in every predetermined
number of the slots 31 (every six slots 31 in this embodiment). The
turn portions 45 project from the axial ends of the stator core
30.
[0049] Each of the windings 40 is wave-wound along the
circumferential direction with one end thereof being projected from
the axial end of the stator core 30. One phase winding of the
stator winding 4 is constituted by two of the winding 40 wave-wound
along the circumferential direction and connected to each other at
other ends thereof. The in-slot portions 44 of these two windings
40 are accommodated in the same slots 31. The in-slot portions 44
of a first one of the two windings 40 (hereinafter referred to as
the winding 40a) and the in-slot portions 44 of a second one of the
two windings 40 (hereinafter referred to as the winding 40b) are
accommodated such that they alternate in the depth direction in the
slots. A connecting portion 45 at which the first and second
windings 40a and 40b are connected to each other is formed as a
turn-round portion 46 constituted by a specific one of the in-slot
portions 44.
[0050] As shown in FIG. 9, the stator winding 4 is constituted by
six phase windings (U1, U2, V1, V2, W1 and W2) each of which is
constituted by the first and second windings 40a and 40b. The first
and second windings 40a and 40b of each of the phase windings are
connected in series to each other at their ends not connected to
the neutral point, or phase terminals.
[0051] The stator winding 4 is fabricated by preparing a wire
assembly as shown in FIG. 9, and convolving this wire assembly by a
predetermined number of times (four times, for example) with the
turn-round portions 46 being located on the axial center side. As
shown in FIG. 8, the fabricated stator winding 4 is shaped such
that the in-slot portions 44 of each of the phase windings are
lined in the radial direction, and spaced by a small distance along
the circumferential direction.
[0052] The stator core 30 is assembled to the stator winding 4 in
the following way to manufacture the stator 3 of the electric
rotating machine.
[0053] First, the tooth portions 320 of the core member 32 are
folded back radially outwardly toward the core back portion 321. As
a result, a hollow portion is formed having a diameter slightly
larger than that of the stator winding 4 at the axial center
portion of the core member 32. In the state of the tooth portions
320 being folded back, the stator winding 4 is inserted into the
hollow portion, and the core member 32 is slid along the axial
direction of the core member 32. When the core member 320 reaches a
position which is at a predetermined distance from the axial end of
the stator winding 4, the tooth portions 320 which have been folded
back unfold and extended radially inwardly to return to their
original shape (the shape of thin plate) due to their resiliency.
As a result, each of the tooth portions 320 radially penetrates
between the adjacent in-slot portions of the stator winding 4.
Thus, each of the in-slot portions 44 is accommodated between each
adjacent two of the tooth portions 320.
[0054] In this state, the core member 32 is slid to a predetermined
axial position of the stator winding 4, and held there.
[0055] In this way, a predetermined number of the core members 32
are assembled to the stator winding 4 successively.
[0056] In the above way, the tooth portions 320 penetrate through
the stator winding 4 by their self-unfolding movement when the core
member 32 is assembled. However, the folded tooth portions 320 may
be unfolded by use of an appropriate jig.
[0057] Thereafter, as shown in FIG. 11, the divided core members 33
are assembled to both axial ends of the laminated core members 32.
The divided core members 33 are assembled in a direction from
radially outside of the stator winding 4 to the axial center of the
stator winding 4. By assembling the divided core members 33, gaps
between the both end surfaces of the laminated core members 32 and
the end surfaces of the stator winding 4 are filled.
[0058] At the time of laminating the core members 32 and the
divided core members 33, an insulating film may be inserted between
each of them.
[0059] The laminated body of the core members 32 and the divided
core members 33 is fitted with band-like fittings 34 to complete
the stator core 30. It is preferable that the laminated body is
compressed in the axial direction at this time. The stator core 30
has high rigidity because the divided core members 33 and the
fittings 34 are joined together. In this embodiment, although the
fittings 34 are joined to the divided core members 33, they may be
joined to the core members 32.
[0060] As apparent from the above description, since the stator 3
of the electric rotating machine 1 of this embodiment is not
divided in the circumferential direction, the magnetic
characteristic is not degraded unlike the conventional stator
constituted by a plurality of divided cores in which its magnetic
characteristic is degraded at the boundaries between each of the
divided cores. Therefore, the electric rotating machine 1 of this
embodiment can prevent lowering of performance due to degradation
of the magnetic characteristic.
[0061] In addition, in this embodiment, since the core member 32 is
made of amorphous metal, iron loss of the stator core 30 is small,
and accordingly, degradation of the magnetic characteristic of the
stator core 30 due to iron loss can be also suppressed. The effect
of the reduction of iron loss becomes large as the rotational speed
of the rotor increases.
Second Embodiment
[0062] As shown in FIGS. 12 and 13, a second embodiment of the
invention differs from the first embodiment only in that the
divided core members 33 are disposed at not only the axial ends of
the stator core 33, but also at a position in between the laminated
core members 32.
[0063] In the second embodiment, the number of joint portions
between the stator cores 30 and the fittings 34 is larger than that
in the first embodiment. Accordingly, the rigidity of the stator
core 30 can be further improved compared to the first
embodiment.
[0064] Other than this, the second embodiment provides the same
advantages provided by the first embodiment.
Third Embodiment
[0065] A third embodiment of the invention differs from the first
embodiment only in that the third embodiment uses a fitting 35
different from the fitting 34 used in the first embodiment to fix
the core members 32 and the divided core members 33 together.
[0066] As shown in FIG. 14, in the third embodiment, the fitting 35
joined to the divided core members 33 is a cylindrical member into
which the laminated body of the core members 32 and the divided
core members 33 are fitted. Accordingly, the rigidity of the stator
core 30 can be further improved compared to the first
embodiment.
[0067] Other than this, the third embodiment provides the same
advantages provided by the first embodiment.
Fourth Embodiment
[0068] A fourth embodiment of the invention differs from the first
embodiment only in that the shape of the tooth portions 320 after
being folded back is different from that in the first
embodiment.
[0069] As shown in FIG. 15, in this embodiment, the front end
portion of the tooth portion 320 is bent facing the direction in
which the core member 32 is slid. By folding back the tooth portion
320 in a state of being bent, the distance between the core back
portion 321 and the outer periphery of the stator winding 4 can be
reduced.
[0070] Other than this, the fourth embodiment provides the same
advantages provided by the first embodiment.
Fifth Embodiment
[0071] A fifth embodiment of the invention differs from the first
embodiment only in that the core member 32 is formed with slits
extending along the tooth portions 320 at joint portions between
the teeth portions 320 and the core back portion 320 as shown in
FIG. 16.
[0072] In the fifth embodiment, since the tooth portions 320 can be
folded back easily because of the provision of the slits,
workability of assembling the core members 32 to the stator winding
4 can be improved.
[0073] Other than this, the fifth embodiment provides the same
advantages provided by the first embodiment.
Sixth Embodiment
[0074] A sixth embodiment of the invention differs from the first
embodiment only in that the core member 32 is evenly divided in the
circumferential direction into a plurality of portions as shown in
FIG. 17, while satisfying the requirement that the magnetic
characteristic of the stator core 30 is not degraded. Other than
this, the sixth embodiment provides the same advantages provided by
the first embodiment.
[0075] The above explained preferred embodiments are exemplary of
the invention of the present application which is described solely
by the claims appended below. It should be understood that
modifications of the preferred embodiments may be made as would
occur to one of skill in the art.
* * * * *