U.S. patent application number 09/783976 was filed with the patent office on 2001-10-18 for stator iron core of electric motor, manufacturing method thereof, electric motor, and compressor.
This patent application is currently assigned to MITSUBISHI DENKI KABUSHIKI KAISHA. Invention is credited to Akita, Hiroyuki, Arai, Toshio, Kato, Masaki, Kazama, Osamu, Masumoto, Kouji, Miyajima, Takuhito, Oikawa, Tomoaki, Tajima, Tsuneyoshi.
Application Number | 20010030483 09/783976 |
Document ID | / |
Family ID | 26585744 |
Filed Date | 2001-10-18 |
United States Patent
Application |
20010030483 |
Kind Code |
A1 |
Masumoto, Kouji ; et
al. |
October 18, 2001 |
Stator iron core of electric motor, manufacturing method thereof,
electric motor, and compressor
Abstract
The present invention aims to provide a stator iron core of an
electric motor which can eliminate the reduction of efficiency,
vibration or noise of the electric motor by decreasing stress
generated at a bottom portion of a slot on manufacturing or
integrating the electric motor. Plural magnetic pole segments, each
having a back yoke portion and a teeth portion projected from the
back yoke portion, are connected so as to be bendable via a
connection portion provided to the back yoke portion. After winding
the coil wire, a stator iron core of the electric motor is
circularly formed by bending the connection portion of the plural
magnetic pole segments. In the stator iron core, the bottom portion
of the slot constituted by the back yoke portion and the teeth
portion is made to have a curved line after the stator iron core is
circularly formed.
Inventors: |
Masumoto, Kouji; (Tokyo,
JP) ; Oikawa, Tomoaki; (Tokyo, JP) ; Tajima,
Tsuneyoshi; (Tokyo, JP) ; Kazama, Osamu;
(Tokyo, JP) ; Kato, Masaki; (Tokyo, JP) ;
Arai, Toshio; (Tokyo, JP) ; Miyajima, Takuhito;
(Tokyo, JP) ; Akita, Hiroyuki; (Tokyo,
JP) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT PC
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Assignee: |
MITSUBISHI DENKI KABUSHIKI
KAISHA
Tokyo
JP
|
Family ID: |
26585744 |
Appl. No.: |
09/783976 |
Filed: |
February 16, 2001 |
Current U.S.
Class: |
310/216.008 ;
310/216.009; 310/51 |
Current CPC
Class: |
H02K 15/024 20130101;
H02K 1/165 20130101 |
Class at
Publication: |
310/216 ;
310/254; 310/51 |
International
Class: |
H02K 001/00; H02K
001/12; H02K 005/24 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 21, 2000 |
JP |
2000-042831 |
Sep 18, 2000 |
JP |
2000-281176 |
Claims
What is claimed is
1. A stator iron core of an electric motor comprising plural
magnetic pole segments, wherein each of the plural magnetic pole
segments has a back yoke portion and a teeth portion projected from
the back yoke portion, wherein each of the plural magnetic pole
segments is connected so as to be bendable via a connection portion
provided to the back yoke portion, wherein the stator iron core is
circularly formed by bending the connection portions of the plural
magnetic pole segments, and wherein each of the plural magnetic
pole segments is made so that a bottom portion of a slot
constituted by the back yoke portion and the teeth portion has a
curved line after circularly forming the stator iron core.
2. The stator iron core of the electric motor claimed in claim 1
further comprising an insulator member placed on the teeth portion
for covering a projected portion of the back yoke portion and
covering a wall surface of the teeth portion, wherein a wall
surface covering the back yoke portion of the insulator member
makes an angle of around 90.degree. with the wall surface covering
the teeth portion of the insulator member.
3. A stator iron core of an electric motor comprising plural
magnetic pole segments, wherein each of the plural magnetic pole
segments has a back yoke portion and a teeth portion projected from
the back yoke portion, wherein each of the plural magnetic pole
segments is connected so as to be bendable via a connection portion
provided to the back yoke portion, wherein the stator iron core is
circularly formed by bending the connection portions of the plural
magnetic pole segments, and wherein the magnetic pole segment has a
notch on an outer circumference of the back yoke portion.
4. The stator iron core of the electric motor claimed in claim 3,
wherein the notch is provided at a place opposite to the connection
portion in an axial direction on the outer circumference of the
back yoke portion.
5. The stator iron core of the electric motor claimed in claim 3,
wherein the notch is provided at a place opposite to the teeth
portion in an axial direction on the outer circumference of the
back yoke portion.
6. A stator iron core of an electric motor comprising plural
magnetic pole segments which are connected and confronted by plural
confronting surfaces, wherein two of the confronting surfaces are
made to have V-shaped surfaces.
7. The stator iron core of the electric motor claimed in claim 6,
wherein the stator iron core includes laminated iron core members,
each of which has the plural magnetic pole segments connected via
thin connection portions, wherein the plural confronting surfaces
include plural confronting surfaces of the connection portions at
both sides of the connection portions, and the two of the
confronting surfaces of the end portions having the V-shaped
surfaces, wherein the stator iron core is circularly formed by
bending each of the connection portions, joining the plural
confronting surfaces of the connection portions, and joining the
two of the confronting surfaces of the end portions.
8. The stator iron core of the electric motor claimed in claim 6,
wherein each of the two of the confronting surfaces having the
V-shaped surfaces is formed by combining a first arc and a second
arc, and centers of the first arc and the second arc match to a
turning center of bending the connection portion of any magnetic
pole segment of the stator.
9. The stator iron core of the electric motor claimed in claim 6,
wherein the two of the confronting surfaces form a jut having a top
point projected to an outer circumference side of the stator iron
core of the electric motor, and the top point of the jut is located
inside of the outer circumference of the stator iron core of the
electric motor.
10. An electric motor comprising the stator iron core of the
electric motor claimed in claim 1.
11. An electric motor comprising the stator iron core of the
electric motor claimed in claim 3.
12. An electric motor comprising the stator iron core of the
electric motor claimed in claim 6.
13. A compressor comprising the electric motor claimed in claim
10.
14. A compressor comprising the electric motor claimed in claim
11.
15. A compressor comprising the electric motor claimed in claim
12.
16. A method for manufacturing a stator iron core of an electric
motor, comprising: making plural magnetic pole segments, each of
which has a back yoke portion and a teeth portion projected from
the back yoke portion; connecting the plural magnetic pole segments
so as to be bendable via a connection portion provided to the back
yoke portion; circularly forming the stator iron core by bending
the connection portion of the plural magnetic pole segments after
winding the coil wire, and wherein the making the plural magnetic
pole segments includes making projected portions so that a bottom
portion of a slot constituted by the back yoke portion and the
teeth portion has a curved line when the stator iron core is
circularly formed.
17. A method for manufacturing a stator iron core of an electric
motor, comprising: making plural magnetic pole segments, each of
which has a back yoke portion and a teeth portion projected from
the back yoke portion; providing a notch on an outer circumference
of the back yoke portion; connecting the plural magnetic pole
segments so as to be bendable via a connection portion provided to
the back yoke portion; and circularly forming the stator iron core
by bending the connection portion of the plural magnetic pole
segments after winding the coil wire.
18. A method for manufacturing a stator iron core of an electric
motor, comprising: making plural magnetic pole segments connected
via connection portions, having two end portions, wherein each of
the plural magnetic pole segments has confronting surfaces at both
sides of the connection portions; making a V-shaped convex contact
portion on the confronting surface of one of the two end portions;
making a V-shaped concave contact portion on the confronting
surface of another of the two end portions; joining the confronting
surfaces of the connection portions; and finally joining the
confronting surfaces of the end portions so as to form the stator
iron core.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an electric motor driving a
compressor used for an air conditioner or a freezer, in particular,
to a stator iron core of the electric motor and a method for
manufacturing the stator iron core of the electric motor.
[0003] 2. Description of the Related Art
[0004] FIG. 13 is a plan view of a conventional stator of an
electric motor disclosed by the same applicant in Japanese Patent
Application No. 11-020128. In the figure, a reference numeral 3
shows a plate-shaped core segment (magnetic pole segment) made of
magnetic material. At one end of the magnetic pole segment, a
concave portion 3a and a convex portion 3b are formed on both
surfaces as a connection means. At the same time, an end face 3c of
the magnetic pole segment having an arc shape (male shape) is
formed on a circumference of a circle having the same center as the
center of the concave portion 3a and the convex portion 3b. At the
other end of the segment, an end face 3d having an arc shape
(female shape) is formed so as to be engaged with an end face 3c of
an adjoining magnetic pole segment 3. A reference numeral 4 shows a
first iron core member in which plural magnetic pole segments 3 are
aligned via the end face 3c and the end face 3d.
[0005] FIG. 14 is a cross sectional view taken along the line DD of
FIG. 10.
[0006] As shown in FIG. 14, a reference numeral 5 shows a second
iron core member in which plural magnetic pole segments 3 are
aligned in the longitudinal direction (as shown by an arrow X). The
first iron core member 4 and the second iron core member 5 are
stacked or laminated alternately. In the stacking direction (as
shown by an arrow Y), the concave portion 3a of the magnetic pole
segment 3 and the convex portion 3b of the adjoining magnetic pole
segment are engaged, so that both magnetic pole segments 3 are
connected in the longitudinal direction (as shown by the arrow X)
so as to rotate around the center of the concave portion 3a and the
convex portion 3b in the direction of an arrow R. A reference
numeral 6 shows a coil wire wound around each magnetic pole segment
3, and 7 shows an iron core formed circularly by turning the
concave portion 3a and the convex portion 3b of each magnetic pole
segment 3 made by laminating both iron core members.
[0007] In the following, a method for manufacturing the
conventional iron core structured as described above will be
explained. FIG. 15 shows a magnetic member plate for manufacturing
the magnetic pole segment 3.
[0008] As the first step for processing the first iron core member
4, surrounding portions of the both end faces 3c and 3d are formed
by punching (or stamping) out portions shown by a real line within
a hatched portion at a location indicated by an arrow A in FIG. 15.
As the first step for processing the second iron core member 5,
surrounding portions of the both end faces 3c and 3d are formed by
punching portions shown by a real line within a hatched portion at
a location indicated by an arrow B in FIG. 15. By the above
punching operation, the concave portion 3a and the convex portion
3b, which can be engaged with each other, are formed on both
surfaces of the end portions, on which the arc end face 3c of the
magnetic pole segment 3 are made as shown in FIG. 16. At the same
time, a hole portion 3h is formed on the magnetic pole segment 3 of
the top layer so as to be engaged with the convex portion 3b of the
magnetic pole segment 3 of the lower layer.
[0009] Next, at a location indicated by an arrow C in FIG. 15, the
first iron core member 4 and the second iron core member 5 are
formed by serially and alternately punching a portion shown by a
real line within a hatched portion, that is, a surrounding portion
of the both end faces 3c and 3d, which are formed at the location
indicated by the arrow A, and a surrounding portion of the both end
faces 3c and 3d, which are formed at the location indicated by the
arrow B. These iron core members 4, 5 are sequentially and
alternately stacked or laminated within a metal stacker.
[0010] Subsequently, the coil wire 6 is wound, and the iron core 7
can be circularly formed by turning the concave portion 3a and the
convex portion 3b, which are engaged in the laminating direction,
of each magnetic pole segment 3.
[0011] FIG. 17 shows a part of the iron core which has been
circularly formed. In FIG. 17, 2 shows a slot which is a space for
winding the coil wire 6. Further, 2a shows a bottom portion of the
slot 2 which has an angular portion made by abutting straight line
portions 2b of the magnetic pole segment 3 and of the adjoining
magnetic pole segment 3. In FIG. 17, the coil wire 6, which exists,
is not illustrated for clarifying the explanation.
[0012] FIGS. 18 and 19 show a conventional stator iron core of an
electric motor disclosed by the Japanese Unexamined Patent
Publication No. HEI 9-191588. As shown in FIG. 18, predetermined
pieces of magnetic material are staked or laminated, in which
plural magnetic pole segments 101 are connected via a thin
connection portion 102. Confronting surfaces 102a and 102b of the
connection portion are provided on both sides of the thin
connection portion 102. Further, confronting surfaces 101b and 101c
are provided on ends of the magnetic pole segments 101 located at
far ends. The confronting surfaces 101b and 101c have the same
shape as the confronting surfaces 102a and 102b.
[0013] A coil wire (not shown in the figure) is would around each
magnetic pole segment in the stator structured above. As shown in
FIG. 19, each thin connection portion 102 is bent, the confronting
surfaces 102a and 102b of the connection portion located on both
sides of the thin connection portion 102 are joined, and finally,
the confronting surfaces 101b and 101c of the end portions are
joined to circularly form the stator iron core of the electric
motor.
[0014] The conventional stator iron core of the electric motor is
structured as shown in FIG. 13. The bottom portion 2a of the slot
2, which is made by circularly forming the stator iron core, has a
fine angle as shown in FIG. 17, so that the stress of the load is
concentrated to that angular portion when the load is applied to
the bottom portion on circularly forming the iron core 7. Further,
when the electric motor is mounted in a compressor, etc. by fixing
into a housing and the like of the compressor with shrink-fitting
(to insert the electric motor into the expanded housing by heating)
or press-fitting (to insert the electric motor into the tight
housing by pressure), the fixing force is concentrated to the
angular portion. Accordingly, the performance of the magnetic
material is reduced, which causes problems that the efficiency of
the electric motor is reduced, it becomes difficult to keep a
sufficient stiffness, and further, vibration or noise may be
generated during the driving of the electric motor.
[0015] The conventional stator iron core of the electric motor is
structured as shown in FIG. 13. Accordingly, when the electric
motor is mounted in the compressor by fixing in the housing and the
like with shrink-fitting or press-fitting, an outer circumference
of the stator iron core around the concave portion 3a and the
convex portion 3b, which rotate when the iron core is circularly
formed, may contact with an inner perimeter of the housing. This
means the stator iron core tend to be influenced by the dimensional
precision of the housing and the like, namely, a circularity of the
outer circumference and the inner circumference of the stator iron
core of the electric motor tends to become worse by the contact
force at the time of shrink-fitting or press-fitting. Further, when
the circularity becomes worse, an air gap between the stator and
the rotor becomes irregular at the time of driving the electric
motor. This may generate magnetic unbalance of the electric motor,
and also causes a problem to generate noise or vibration.
[0016] The conventional stator iron core of the electric motor is
structured as shown in FIGS. 18 and 19. Accordingly, the
confronting surfaces 101b and 101c of the end portions are easily
dislocated in the radius direction at the time of circularly
forming the stator, which makes it difficult to keep the mechanical
precision of the stator. Therefore, when the stator is assembled in
the electric motor, the magnetic performance of the magnetic
material is decreased to cause problems that the efficiency of the
electric motor becomes worse, the magnetic unbalance may be
generated, and vibration or noise may be generated on driving the
motor.
[0017] Further, in the above example, the connection portion is
made thin. Even if the connection portion is made bendable by some
means in the stator, the confronting surfaces 101b and 101c of the
end portions are easily dislocated in the radius direction, which
causes the same problem as above.
[0018] Further, in the above example, the confronting surfaces 102a
and 102b of the connection portion and the confronting surfaces
101b and 101c of the end portions have a straight line portion.
Even if the portions have an arc portion, the confronting surfaces
101b and 101c of the end portions are easily dislocated in the
radius direction, which causes the same problem as above.
SUMMARY OF THE INVENTION
[0019] The present invention aims to provide the stator iron core
of the electric motor which improves the efficiency of the electric
motor and reduces vibration or noise by relieving the stress
applied to the bottom portion of the slot at the time of
manufacturing or integrating the electric motor.
[0020] Further, the present invention aims to enable to easily keep
the good mechanical precision at the time of manufacturing the
electric motor, and aims to decrease the reduction of efficiency,
the vibration or noise of the electric motor.
[0021] According to one aspect of the present invention, in a
stator iron core of an electric motor having plural magnetic pole
segments,
[0022] each of the plural magnetic pole segments has a back yoke
portion and a teeth portion projected from the back yoke
portion,
[0023] each of the plural magnetic pole segments is connected so as
to be bendable via a connection portion provided to the back yoke
portion,
[0024] the stator iron core is circularly formed by bending the
connection portions of the plural magnetic pole segments, and
[0025] each of the plural magnetic pole segments is made so that a
bottom portion of a slot constituted by the back yoke portion and
the teeth portion has a curved line after circularly forming the
stator iron core.
[0026] According to another aspect of the invention, in a stator
iron core of an electric motor having plural magnetic pole
segments,
[0027] each of the plural magnetic pole segments has a back yoke
portion and a teeth portion projected from the back yoke
portion,
[0028] each of the plural magnetic pole segments is connected so as
to be bendable via a connection portion provided to the back yoke
portion,
[0029] the stator iron core is circularly formed by bending the
connection portions of the plural magnetic pole segments, and
[0030] the magnetic pole segment has a notch on an outer
circumference of the back yoke portion.
[0031] According to another aspect of the invention, in a stator
iron core of an electric motor comprising plural magnetic pole
segments which are connected and confronted by plural confronting
surfaces,
[0032] two of the confronting surfaces are made to have V-shaped
surfaces.
[0033] According to another aspect of the invention, an electric
motor includes the stator iron core of the invention.
[0034] According to another aspect of the invention, a compressor
includes the electric motor of the invention.
[0035] According to another aspect of the invention, a method for
manufacturing a stator iron core of an electric motor, having:
[0036] making plural magnetic pole segments, each of which has a
back yoke portion and a teeth portion projected from the back yoke
portion;
[0037] connecting the plural magnetic pole segments so as to be
bendable via a connection portion provided to the back yoke
portion;
[0038] circularly forming the stator iron core by bending the
connection portion of the plural magnetic pole segments after
winding the coil wire, and
[0039] in the method, the making the plural magnetic pole segments
includes making projected portions so that a bottom portion of a
slot constituted by the back yoke portion and the teeth portion has
a curved line when the stator iron core is circularly formed.
[0040] According to another aspect of the invention, a method for
manufacturing a stator iron core of an electric motor, having:
[0041] making plural magnetic pole segments, each of which has a
back yoke portion and a teeth portion projected from the back yoke
portion;
[0042] providing a notch on an outer circumference of the back yoke
portion;
[0043] connecting the plural magnetic pole segments so as to be
bendable via a connection portion provided to the back yoke
portion; and
[0044] circularly forming the stator iron core by bending the
connection portion of the plural magnetic pole segments after
winding the coil wire.
[0045] According to yet another aspect of the invention, a method
for manufacturing a stator iron core of an electric motor,
having:
[0046] making plural magnetic pole segments connected via
connection portions, having two end portions, wherein each of the
plural magnetic pole segments has confronting surfaces at both
sides of the connection portions;
[0047] making a V-shaped convex contact portion on the confronting
surface of one of the two end portions;
[0048] making a V-shaped concave contact portion on the confronting
surface of another of the two end portions;
[0049] joining the confronting surfaces of the connection portions;
and
[0050] finally joining the confronting surfaces of the end portions
so as to form the stator iron core.
BRIEF EXPLANATION OF THE DRAWINGS
[0051] A complete appreciation of the present 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
accompanying drawings, wherein:
[0052] FIG. 1 shows a plan view of a stator of an electric motor
according to the first embodiment of the present invention;
[0053] FIG. 2 is a plan view showing a portion of the electric
motor and explaining how to wind a coil wire of the stator of the
electric motor according to the first embodiment of the
invention;
[0054] FIG. 3 shows a plan view of a stator of an electric motor
according to the second embodiment of the present invention;
[0055] FIG. 4 shows a plan view of a stator of an electric motor
according to the third embodiment of the present invention;
[0056] FIG. 5 shows a plan view of a band-type stator of an
electric motor according to the fourth embodiment of the present
invention;
[0057] FIG. 6 shows a plan view of a stator of an electric motor
circularly formed according to the fourth embodiment of the present
invention;
[0058] FIG. 7 shows a plan view of a stator of an electric motor
just before circularly formed according to the fifth embodiment of
the present invention;
[0059] FIG. 8 show a plan view of a stator of an electric motor
circularly formed according to the sixth embodiment of the present
invention;
[0060] FIG. 9 shows a plan view of an electric motor according the
seventh embodiment;
[0061] FIG. 10 shows a cross sectional view of a compressor
according to the seventh embodiment taken along vertically;
[0062] FIG. 11 shows a top view of the compressor of the seventh
embodiment on integrating the electric motor;
[0063] FIG. 12 shows a partial enlarged view of the compressor on
integrating the electric motor (an enlarged view of a portion
indicated A of FIG. 11);
[0064] FIG. 13 shows a plan view of a conventional electric
motor;
[0065] FIG. 14 shows a plan view of a portion of a conventional
electric motor;
[0066] FIG. 15 shows a concept for explaining a conventional method
for manufacturing the electric motor.;
[0067] FIG. 16 shows a plan view of a portion of the conventional
electric motor;
[0068] FIG. 17 shows a plan view of a portion of the conventional
electric motor.
[0069] FIG. 18 shows a plan view of a stator of the conventional
electric motor; and
[0070] FIG. 19 shows a plan view of the stator of the conventional
electric motor.
DESCRIPTION OF PREFERRED EMBODIMENTS
Embodiment 1
[0071] In the following, the first embodiment of the present
invention will be explained by referring to the figures.
[0072] FIGS. 1 and 2 show the first embodiment. FIG. 1 is a plan
view of a stator of an electric motor, and FIG. 2 is a plan view
showing a part of the electric motor and explaining how to wind a
coil wire of the stator of the electric motor.
[0073] In FIG. 1, a reference numeral 1 shows a plate-shaped core
segment (magnetic pole segment) made of magnetic material, and a
reference numeral 9 shows a connection portion (also called as a
joint portion) consisting of a concave portion 3a and a convex
portion 3b provided to both surfaces of one end of the magnetic
pole segment 3 as a connection means. 4 shows the first iron core
member in which plural magnetic pole segments 3 are aligned via an
end face 3c and an end face 3d of each segment.
[0074] A reference numeral 5 shows the second iron core member in
which plural magnetic pole segments 3 are aligned, and the second
iron core member and the first iron core member are stacked or
laminated alternately. The concave portion 3a of a certain magnetic
pole segment 3 is engaged with the convex portion 3b of an
adjoining magnetic pole segment so that the magnetic pole segments
3 are connected so as to turn freely around a center of the concave
portion 3a and the convex portion 3b. A reference numeral 7 shows
an iron core which is circularly formed by turning the concave
portion 3a and the convex portion 3b of the connection portion 9 of
each magnetic pole segment 3 made by laminating both iron core
members.
[0075] A reference numeral 3e shows a back yoke portion of the
magnetic pole segment 3, and 3f shows a teeth portion.
[0076] 2 shows a slot formed by the back yoke portion 3e and the
teeth portion 3f, and 2a shows a bottom portion of the slot. The
bottom portion 2a of the slot is constituted by the back yoke
portions 3e of the first iron core member 4 and the second iron
core member 5. The bottom portion 2a has a curved line and does not
have a fine angle.
[0077] A reference numeral 8 shows an insulator member coated on
the teeth portion 3f to cover a wall of the teeth portion 3f. The
insulator member wall of the back yoke portion makes around
90.degree. with the insulator member wall of the teeth portion 3f,
and further the insulator member 8 covers a projected portion 3g of
the back yoke portion 3e.
[0078] A coil wire is wound in the slot 2 in this embodiment,
however, the coil wire is not illustrated in FIG. 1 for clarifying
the explanation. An illustration of the insulator member 8 is
partially omitted, too.
[0079] The connection portion 9 is provided at an outer
circumference side of the back yoke portion 3e. At around the
connection portion 9, the end faces 3c and 3d form a male shape 3i
and a female shape 3j, each having a half circular shape with a
center of the connection portion 9. On the other side, a straight
line portion 3k and a straight line portion 31 are formed from
around the connection portion 9 toward the projected portion 3g.
Further, by providing the projected portion 3g as shown in FIG. 1,
it becomes possible to make a length L1 of the end portion of the
back yoke portion 3e in the radius direction equal to a length L2
of the center portion of the back yoke portion 3e in the radius
direction. Another structure can be made in which a length L of the
back yoke portion 3e in the radius direction has the same size at
any portion (L=L1=L2) and the curved line of the bottom portion 2a
of the slot is made to be an arc of a circle having a center which
is a center W of a rotation axis of the rotor.
[0080] The stator is structured as described above, the bottom
portion 2b of the slot forms the curved line, so that the stress of
the load is distributed to the straight line portions 3k and 31
formed from around the connection portion 9 toward the projected
portion 3g, and is not concentrated to the bottom portion 2a of the
slot at the time of forming the iron core 7 circularly or at the
time of fixing the stator of the electric motor in the housing and
the like by press-fitting or shrink-fitting. Therefore, the
magnetic performance is not lost, and further problems can be
eliminated that the efficiency of the electric motor becomes worse,
sufficient stiffness cannot be kept, or vibration or noise is
generated on driving the electric motor.
[0081] Further, when the bottom portion 2a of the slot is formed by
the curved line, the portion 3g is projected. The coil wire 6 is
wound so that a nozzle keeps parallel to the teeth portion 3f as
shown in FIG. 2. At this time, the projected portion 3g may injure
the coil wire on winding the coil wire 6, and further, an
undesirable space, in which the coil wire cannot be wound to avoid
injuring the coil wire, may be generated at the back yoke portion
3e side. However, since the insulator member 8 is coated on the
teeth portion 3f to cover the projected portion 3g, the coil wire 6
can be wound without the undesirable space and without being
injured.
Embodiment 2
[0082] In the following, the second embodiment of the present
invention will be explained referring to the figures.
[0083] FIG. 3 shows a plan view of the stator of the electric motor
according to the second embodiment. In FIG. 3, a reference numeral
3 shows a plate-shaped core segment (magnetic pole segment) made of
the magnetic material. A reference numeral 9 shows a connection
portion constituted by a concave portion 3a and a convex portion 3b
provided to both surfaces of one end of the magnetic pole segment 3
as a connection means. 4 shows the first iron core member in which
plural magnetic pole segments 3 are aligned via an end face 3c and
an end face 3d of each segment.
[0084] A reference numeral 5 shows the second iron core member in
which plural magnetic pole segments 3 are aligned, and the second
iron core member and the first iron core member are stacked or
laminated alternately. The concave portion 3a of a certain magnetic
pole segment 3 is engaged with the convex portion 3b of an
adjoining magnetic pole segment so that the magnetic pole segments
3 are connected so as to turn freely around a center of the concave
portion 3a and the convex portion 3b. A reference numeral 7 shows
an iron core which is circularly formed by turning the concave
portion 3a and the convex portion 3b of the connection portion 9 of
each magnetic pole segment 3 made by laminating both iron core
members.
[0085] A reference numeral 3e shows a back yoke portion of the
magnetic pole segment 3, and 3f shows a teeth portion. 10 shows a
notch formed at a place opposite to the connection portion 9 and
extended to the direction of rotation axis of the rotor. A coil
wire is wound in the slot 2 in this embodiment, however, the coil
wire is not illustrated in FIG. 3 for clarifying the
explanation.
[0086] When the stator of the electric motor is fixed in the
housing and the like by press-fitting or shrink-fitting, since the
notch is formed at the place opposite to the connection portion 9
and extended to the direction of rotation axis of the stator, the
stator of the electric motor is not directly pressed against the
housing around the connection portion 9. Accordingly, the notch 10
with an appropriate size can adjust the load applied to the
connection portion 9 when the stator of the electric motor is
inserted in the housing and the like by press-fitting or
shrink-fitting.
[0087] Consequently, it is possible to minimize the stress applied
to the connection portion 9 with keeping the sufficient stiffness
by selecting an appropriate length U of the notch 10 in the
circumference direction.
[0088] Further, the insulator film covering the magnetic material
is removed from the connection portion 9 on forming the iron core
7, the concave portion 3a or the convex portion 3b. Accordingly,
the insulation resistance is lowered between iron core members 4
and 5, eddy current is generated on driving the electric motor, and
further, the efficiency of the motor is reduced.
[0089] The above problem can be also solved by the present
embodiment. By changing the length U of the notch 10 in the
circumference direction, the contact power between the inside of
the housing and the outer circumference of the stator of the
electric motor can be minimized while keeping a required contact
power. By minimizing the contact power, the insulation resistance
of each of the iron core members 4 and 5 in the direction of
rotation axis is not lowered or increased. Therefore, it becomes
possible to minimize the reduction of the efficiency of the
electric motor caused by the eddy current generated in the iron
core 7. Therefore, sufficient stiffness of the stator can be kept
without losing the magnetic performance of the magnetic material or
reducing the efficiency of the electric motor caused by the eddy
current. Embodiment 3.
[0090] In the following, the third embodiment of the present
invention will be explained referring to the figures.
[0091] FIG. 4 shows a plan view of the stator of the electric motor
according to the third embodiment. In FIG. 4, a reference numeral 3
shows a plate magnetic pole segment made of the magnetic material.
A reference numeral 9 shows a connection portion constituted by a
concave portion 3a and a convex portion 3b provided to both sides
of one end of the magnetic pole segment 3 as a connection means. 4
shows the first iron core member in which plural magnetic pole
segments 3 are aligned via an end face 3c and an end face 3d of
each segment.
[0092] A reference numeral 5 shows the second iron core member in
which plural magnetic pole segments 3 are aligned, and the second
iron core member and the first iron core member are stacked or
laminated alternately. The concave portion 3a of a certain magnetic
pole segment 3 is engaged with the convex portion 3b of an
adjoining magnetic pole segment so that the magnetic pole segments
3 are connected so as to turn freely around a center of the concave
portion 3a and the convex portion 3b. A reference numeral 7 shows
an iron core which is circularly formed by turning the concave
portion 3a and the convex portion 3b of the connection portion 9 of
each magnetic pole segment 3 made by laminating both iron core
members.
[0093] A reference numeral 3e shows a back yoke portion of the
segment 3, and 3f shows a teeth portion. 11 shows a notch formed at
a place opposite to the teeth portion 3f and extended to the
direction of rotation axis of the rotor.
[0094] A coil wire is substantially wound in the slot 2 in this
embodiment, however, the coil wire is not illustrated in FIG. 4 for
clarifying the explanation.
[0095] When the stator of the electric motor is inserted in the
housing and the like by press-fitting or shrink-fitting, since the
contact area can be changed by changing a length T of the notch in
the circumference direction, it becomes possible to minimize the
stress of compression applied to the stator of the electric motor
with the sufficient fixing force.
[0096] Further, the notch 11 is located at the place opposite to
the teeth portion 3f, and the magnetic flux of the place of the
notch is lower compared with other portion of the iron core on
driving the electric motor. Therefore, providing the notch at this
place causes the reduction of the efficiency of the electric motor
less than a case in which the notch is provided at other place of
the iron core.
Embodiment 4.
[0097] In the following, the fourth embodiment of the present
invention will be explained referring to the figures.
[0098] FIGS. 5 and 6 show the fourth embodiment. FIG. 5 shows a
plan view of a band-shaped stator of the electric motor, and FIG. 6
shows a plan view of a stator of the electric motor formed
circularly.
[0099] In FIG. 5, a reference numeral 21 shows a plate-shaped
magnetic pole segment (also called as a core segment), and a
reference numeral 22 shows a thin connection portion provided to
the magnetic pole segment 21. 21a shows a teeth portion of the
magnetic pole segment 21, and 22a and 22b show confronting surfaces
of the connection portion located at both sides of the thin
connection portion 22. 21b and 21c show V-shaped confronting
surfaces of end portions, each of which is located at an opposite
side to the thin connection portion 2 of the magnetic pole segment
21 placed at far end.
[0100] A method for manufacturing the stator of the electric motor
structured as described above will be explained hereinafter. After
the coil wire (not illustrated) is wound around the teeth portion
21a, the thin connection portion 22 of each magnetic pole segment
21 is bent, the confronting surfaces 22a and 22b of the connection
portion are faced so that the location of each magnetic pole
segment 21 is determined. Finally, the confronting surfaces 21b and
21c of the end portions of the both ends are faced to make a
circular form, the form is fixed by welding, etc., and a terminal
wire of the coil wire is electrically connected to make the stator
of the electric motor.
[0101] As the stator is structured as described above, the
relationship of the location of each magnetic pole segment 21
should be determined by each of the confronting surfaces 22a and
22b of the connection portions and the confronting surfaces 21b and
21c of the end portions. Since the confronting surfaces 21b and 21c
of the end portions have V-shapes of male shape and female shape,
the movement of the stator in the radius direction will be
restricted when the V-shape of male shape and the V-shape of female
shape are faced. Accordingly, the mechanical precision of the
stator of the electric motor will be directly determined. It is
possible to easily secure the mechanical precision by improving the
precision of punching the magnetic pole segment 21 and so on.
[0102] In the present embodiment, the connection portion is made
thin, however, the same effect can be brought when the embodiment
is applied to a case in which a connection portion is made by one
of other ways and the stator is circularly formed from the aligned
plural magnetic pole segments 21.
Embodiment 5
[0103] In the following, the fifth embodiment of the present
invention will be explained referring to the figures.
[0104] FIG. 7 shows the fifth embodiment and is a plan view of the
stator of the electric motor just before formed circularly.
[0105] In FIG. 7, a reference numeral 21 shows a plate-shaped
magnetic pole segment made of magnetic material, and a reference
numeral 22 shows a thin connection portion provided to the magnetic
pole segment 21. 22a and 22b show confronting surfaces of the
connection portions located at both sides of the thin connection
portion 22. 21b and 21c show V-shaped confronting surfaces of end
portions, each of which is located at opposite side to the thin
connection portion 2 of the magnetic pole segment 21 placed at far
end.
[0106] The confronting surfaces 21b and 21c of the end portions are
constituted by two arc shapes, the first arc 21d and the second arc
21e. Centers of the arcs are approximately the same to turning
centers S1 and S2 which are turning points for bending the thin
connection portions of any two of the magnetic pole segments
21.
[0107] The stator is structured as described above, turning centers
S1 and S2 of the thin connection portions of specific magnetic pole
segments 21 are centers of the first arc id and the second arc 1e,
respectively, and turning centers S1 and S2 are turning points when
the both far ends of magnetic pole segment are finally to be faced.
Therefore, when the thin connection portion 22 of the specific
magnetic pole segment is bent at last, the magnetic pole segments
21 are not disturbed each other, and the stator can be formed
circularly out of plural magnetic pole segments.
[0108] Accordingly, it is no need to determine an order of bending
magnetic pole segments at bending process, and manufacturing the
stator can be performed more flexibly in the aspect of facilities.
Further, since the disturbance at bending process can be
eliminated, the high reliability can be obtained in manufacturing
the stator of the electric motor.
[0109] In the above embodiment, the connection portion is made
thin. However, the same effect can be obtained by making the
connection portion in one of other ways and the stator is
circularly formed from the aligned plural magnetic pole segments
21.
Embodiment 6
[0110] In the following, the sixth embodiment of the present
invention will be explained referring to the figures.
[0111] FIG. 8 shows a plan view of a part of the stator of the
electric motor according to the sixth embodiment.
[0112] In FIG. 8, a reference numeral 21 shows a plate-shaped
magnetic pole segment made of magnetic material, and 21b and 21c
show V-shaped confronting surfaces of end portions, each of which
is located at the opposite side to a thin connection portion 22 of
the magnetic pole segment 21 placed at far end. 23 shows a jut,
which is formed on facing the confronting surfaces of the end
portions, jutted out to an outer circumference of the stator. The
jut 23 is located inside of the outer circumference of the stator
of the electric motor.
[0113] The stator is structured as described above, on finally
joining both ends of magnetic pole segments, top point of the jut
23 face to the outer circumference. Accordingly, when the
confronting surfaces 21b and 21c of the end portions are joined, it
is possible to easily blow an electric arc to the top point of the
jut 23, which requires to be welded, and possible to weld the
confronting surfaces more sufficiently compared with welding to a
flat plane or an arc plane of the outer circumference.
Embodiment 7
[0114] An embodiment for the electric motor and the compressor will
be explained in the following.
[0115] FIG. 9 shows a plan view of an electric motor employing the
stator iron core of the electric motor according to the first
through fourth embodiments.
[0116] After the coil wire 6 is wound around the insulator member 8
on the teeth portion 3f of the stator iron core 7 of the electric
motor, appropriate electric wire connections are made, the rotor 12
having the rotation axis 13 is inserted into the stator.
Accordingly, the electric motor 14 is formed.
[0117] The application of the present invention is not limited to a
case employing the stator iron core according to the first through
fourth embodiments, but the invention can be also applied to a case
employing the stator iron core according to one embodiment or a
certain combination of more than two embodiments from the first
through sixth embodiments.
[0118] FIG. 10 shows a cross sectional view of the compressor 16
containing the electric motor 14 taken along vertically. FIG. 11
shows a plan view of the compressor 16 when the electric motor is
integrated, and FIG. 12 shows an enlarged view of a portion
indicated as A of FIG. 11.
[0119] The electric motor 14 is integrated into the housing 15 of
the compressor and the like by shrink-fitting or press-fitting,
appropriate electric wire connections are made, and the rotation
axis 13 of the compressor 16 can be driven.
[0120] As shown in the enlarged view of FIG. 12, the notch 11 is
provided at the place opposite to the teeth portion, so that it is
possible to fix the magnetic pole segment 3 by engaging the notch
11 with the winder chuck on winding the coil wire 6. Since the coil
wire 6 is wound around the teeth portion 3f, it is possible to
stably place the magnetic pole segment 3 by fixing the magnetic
pole segment 3 using the notch 11 provided to the place opposite to
the teeth portion 3f. Further, on integrating the electric motor in
the housing 15 of the compressor 16, the notches 10 and 11 can be a
passage for cooling gas or lubricating oil, and on inserting the
electric motor by press-fitting, the contact area can be made
smaller. Accordingly, it becomes easy to insert the electric motor
into the housing 15 of the compressor 16.
[0121] In the stator iron core of the electric motor according to
the first through third embodiments, the magnetic pole segment is
structured so that the bottom portion of the slot constituted by
the back yoke portion and the teeth portion comes to have a curved
line after the stator iron core is formed circularly. Accordingly,
since the bottom portion of the slot has a curved line, on forming
the iron core circularly or fixing the stator of the electric motor
in the housing and the like by press-fitting or shrink-fitting,
compression stress is not concentrated, which avoids to lose the
magnetic performance of the magnetic material. Therefore, the
embodiment of the invention does not reduce the efficiency of the
electric motor, keeps the sufficient stiffness of the electric
motor, and reduces the vibration or noise generated on driving the
electric motor.
[0122] Further, the insulator member is provided to the teeth
portion to cover the projected portion of the back yoke portion as
well as the wall surface of the teeth portion. The wall surface of
the back yoke portion of the insulator member and the wall surface
of the teeth portion of the insulator member make an angle of
around 90.degree.. Therefore, possibility of injuring the coil wire
by the projected portion on winding the coil wire is reduced.
[0123] Further, the notch is provided in the axial direction on the
outer circumference of the back yoke portion at a place opposite to
the connection portion, so that it becomes possible to reduce the
stress generated at the connection portion on forming the iron core
circularly or integrating the stator of the electric motor in the
housing and the like by press-fitting or shrink-fitting, and reduce
the damage caused by eddy current. Therefore, the embodiment of the
invention does not reduce the efficiency of the electric motor,
keeps sufficient stiffness of the electric motor, and reduces the
vibration or noise generated during driving the electric motor.
[0124] Further, the notch is provided in the axial direction at a
place opposite to the connection portion, so that the inner surface
of the housing never contact the connection portion on integrating
the stator in the housing by press-fitting or shrink-fitting, and
the stator is seldom influenced by the dimensional precision of the
housing. Further, since the holding force is applied to both sides
of a place located far from the turning center of the connection
portion, moment, which causes magnetic pole segments to contact
without any space, is loaded to the connection portion. Therefore,
each of the iron core members of the stator iron core of the
electric motor becomes the same status to an iron core member made
by punching (stamping out) as one circular (round) element, so that
circularities of the outer circumference and the inner
circumference of the stator of the electric motor become better.
Consequently, air gap becomes uniform between the stator and the
rotor of the electric motor on driving the motor, which eliminates
magnetic unbalance, and further, reduces the noise or vibration of
the electric motor.
[0125] Further, since the dimensional precisional allowance of the
housing is around some tens .mu.m in the radius direction at
maximum of the circularity, the notch having a depth of more than
0.01 mm in the radius direction will be sufficient to obtain the
above effect.
[0126] Further, the notch is provided on the outer circumference of
the back yoke portion at a place opposite to the teeth portion, so
that the stress of compression can be reduced on forming the iron
core circularly or integrating the stator of the electric motor to
the housing by press-fitting or shrink-fitting. Accordingly, the
embodiment does not reduce the magnetic performance of the magnetic
material nor reduce the efficiency of the electric motor, keeps
sufficient stiffness, and reduces the vibration or noise generated
on driving the electric motor.
[0127] Further, since the stator of the electric motor according to
the fourth through sixth embodiments has V-shaped confronting
surfaces of the end portions, the relationship of the location of
each magnetic pole segment should be determined by each of the
confronting surfaces of the connection portions and the confronting
surfaces of the end portions. Since the confronting surfaces of the
end portions have V-shapes, the movement of the stator in the
radius direction will be restricted when the V-shaped end portions
are faced. Accordingly, the mechanical precision of the stator of
the electric motor will be directly determined. It is possible to
easily secure the mechanical precision by improving the precision
of punching the magnetic pole segment and so on. Therefore, the
electromagnetic noise or vibration caused by a bad mechanical
precision can be reduced, and further, the stator of the electric
motor having high density of coiled wire, high efficiency, low
noise, and low vibration can be easily obtained.
[0128] Each of the V-shaped confronting surfaces of the end portion
is formed by two arc shapes, the first arc and the second arc.
Centers of the arcs are approximately the same as the center of
turning at the time of bending the thin connection portion of any
of the magnetic pole segments, so that the centers of turning of
the thin connection portions of magnetic pole segments are centers
of the first arc and the second arc, respectively, and the centers
of turning are turning points when the both far ends of magnetic
pole segments are to be faced at last. Therefore, when the thin
connection portion of the magnetic pole segment, which is located
between the above specific magnetic pole segments, is bent at last,
the magnetic pole segments are not disturbed each other, and the
stator can be formed circularly out of plural magnetic pole
segments. Accordingly, it is no need to determine an order of
bending magnetic pole segments at bending process, and
manufacturing the stator can be performed more flexibly in the
aspect of facilities. Further, since the interference at bending
process can be eliminated, the high reliability can be obtained in
integrating the stator of the electric motor.
[0129] Since the jut is formed on joining the confronting surfaces
of the end portions and is projected to an outer circumference of
the stator as the top point. The top point of the jut is located
inside of the outer circumference of the stator of the electric
motor, so that the top point of the jut faces to the outer
circumference side which are to be finally joined as both ends of
magnetic pole segments. Accordingly, when the confronting surfaces
of the end portions are joined, it is possible to easily blow an
electric arc to the top point of the jut, which requires to be
welded, and possible to weld the confronting surfaces sufficiently
compared with welding to a flat plane or an arc plane of the outer
circumference.
[0130] Having thus described several particular embodiments of the
present invention, various alterations, modifications, and
improvements will readily occur to those skilled in the art. Such
alterations, modifications, and improvements are intended to be
part of this disclosure, and are intended to be within the spirit
and scope of the present invention. Accordingly, the foregoing
description is by way of example only, and is not intended to be
limiting. The present invention is limited only as defined in the
following claims and the equivalents thereto.
* * * * *