FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
METHOD FOR PRODUCING ELECTRIC MOTOR, ELECTRIC MOTOR, COMPRESSOR,
AND AIR CONDITIONER;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

2
DESCRIPTION
METHOD FOR PRODUCING ELECTRIC MOTOR, ELECTRIC MOTOR, COMPRESSOR,
5 AND AIR CONDITIONER
TECHNICAL FIELD
[0001]
The present invention relates to an electric motor and a
10 method for producing an electric motor.
BACKGROUND ART
[0002]
In a known magnetization technique, permanent magnets
15 (specifically, unmagnetized magnetic materials) of a rotor are
magnetized by using coils (also referred to as winding)
attached to a stator core in general (see, for example, Patent
Reference 1).
20 PRIOR ART REFERENCE
PATENT REFERENCE
[0003]
Patent Reference 1: Japanese Patent Application
Publication No. 2015-91192
25
SUMMARY OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0004]
In a conventional technique, however, when an electric
30 current flows from a source of electrical power for magnetizing
to coils, a large force is generated in the coils, and ends of
the coils in the axial direction of an electric motor, that is,
a coil end, is deformed.
[0005]
3
It is therefore an object of the present invention to
prevent significant deformation of three-phase coils of a
stator in performing magnetization with a rotor disposed inside
the stator.
5
MEANS OF SOLVING THE PROBLEM
[0006]
A method for producing an electric motor according to an
aspect of the present invention is a method for producing an
10 electric motor including a stator and a rotor having a magnetic
pole, the stator having a stator core and three-phase coils
attached to the stator core by distributed winding, the rotor
being disposed inside the stator, and the method includes:
disposing the rotor inside the stator, the rotor having a
15 magnetic material that is not magnetized;
connecting a first phase coil of the three-phase coils to
a positive side of a source of electrical power for
magnetizing;
passing an electric current through the three-phase coils
20 in a state where a center of the magnetic pole of the rotor is
rotated a first angle with respect to a center of a magnetic
pole of the first phase coil in a first rotation direction of
the rotor, the magnetic pole of the first phase coil being
formed when the electric current flows through the first phase
25 coil from the source of electrical power;
switching a connection with the positive side of the
source of electrical power from the first phase coil to a
second phase coil of the three-phase coils; and
passing an electric current through the three-phase coils
30 in a state where the center of the magnetic pole of the rotor
is rotated a second angle with respect to a center of a
magnetic pole of the second phase coil in a second rotation
direction, the magnetic pole of the second phase coil being
formed when the electric current flows through the second phase
4
coil from the source of electrical power, the second rotation
direction being an opposite direction to the first rotation
direction of the rotor.
An electric motor according to another aspect of the
5 present invention includes:
a stator having a stator core and three-phase coils, the
three-phase coils being attached to the stator core by
distributed winding; and
a rotor having a magnetic pole and disposed inside the
10 stator, wherein
the rotor includes
a stator core, and
a permanent magnet disposed in the stator core,
in a plane orthogonal to an axial direction of the rotor,
15 one end side of the permanent magnet is magnetized by passing
an electric current through the three-phase coils in a state
where a center of the magnetic pole of the rotor is rotated a
first angle with respect to a center of a magnetic pole of a
first phase coil of the three-phase coils in a first rotation
20 direction of the rotor, the magnetic pole of the first phase
coil being formed when the electric current flows through the
first phase coil from a source of electrical power for
magnetizing, and
in the plane orthogonal to the axial direction of the
25 rotor, another end side of the permanent magnet is magnetized
by passing an electric current through the three-phase coils in
a state where the center of the magnetic pole of the rotor is
rotated a second angle with respect to a center of a magnetic
pole of a second phase coil of the three-phase coils in a
30 second rotation direction of the rotor, the magnetic pole of
the second phase coil being formed when the electric current
flows through the second phase coil from the source of
electrical power, the second rotation direction being an
opposite direction to the first rotation direction of the rotor.
5
A compressor according to yet another aspect of the
present invention includes:
a closed container;
a compression device disposed in the closed container;
5 and
the electric motor to drive the compression device.
An air conditioner according to still another aspect of
the present invention includes:
the compressor; and
10 a heat exchanger.
EFFECTS OF THE INVENTION
[0007]
The present invention can prevent significant deformation
15 of three-phase coils of a stator in performing magnetization
with a rotor disposed inside the stator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008]
20 FIG. 1 is a plan view schematically illustrating a
configuration of an electric motor according to a first
embodiment of the present invention.
FIG. 2 is a plan view schematically illustrating a
configuration of a rotor.
25 FIG. 3 is a plan view illustrating an example of a stator.
FIG. 4 is a plan view schematically illustrating an
internal configuration of the stator illustrated in FIG. 3.
FIG. 5 is a schematic diagram illustrating an example of
connection in three-phase coils.
30 FIG. 6 is a diagram illustrating an example of a
connection pattern of the three-phase coils in magnetization of
a magnetic material.
FIG. 7 is a diagram illustrating another example of the
connection pattern of the three-phase coils in magnetization of
6
the magnetic material.
FIG. 8 is a diagram illustrating yet another example of
the connection pattern of the three-phase coils in
magnetization of the magnetic material.
5 FIG. 9 is a diagram illustrating still another example of
the connection pattern of the three-phase coils in
magnetization of the magnetic material.
FIG. 10 is a diagram illustrating still another example
of the connection pattern of the three-phase coils in
10 magnetization of the magnetic material.
FIG. 11 is a diagram illustrating still another example
of the connection pattern of the three-phase coils in
magnetization of the magnetic material.
FIG. 12 is a flowchart depicting an example of a process
15 of producing an electric motor.
FIG. 13 is a diagram illustrating an example of a process
for producing an electric motor.
FIG. 14 is a diagram illustrating an example of the
process for producing the electric motor.
20 FIG. 15 is a diagram illustrating an example of the
process for producing the electric motor.
FIG. 16 is a diagram illustrating another example of the
stator.
FIG. 17 is a diagram illustrating a magnetization process
25 in an electric motor as a comparative example.
FIG. 18 is a diagram illustrating an example of an
electromagnetic force in a radial direction occurring in coil
ends of three-phase coils when the three-phase coils are
energized in a process for producing an electric motor.
30 FIG. 19 is a diagram illustrating an example of an
electromagnetic force in an axial direction occurring in the
coil ends of the three-phase coils when the three-phase coils
are energized in the process for producing an electric motor.
FIG. 20 is a graph showing a difference in magnitude of
7
electromagnetic forces in the radial direction among connection
patterns in the three-phase coils when the three-phase coils
are energized in a magnetization process of a magnetic material.
FIG. 21 is a graph showing a difference in magnitude of
5 electromagnetic forces in the axial direction among connection
patterns in the three-phase coils when the three-phase coils
are energized in the magnetization process of a magnetic
material.
FIG. 22 is a graph showing a relationship between an
10 angle [degree] with respect to a reference position and an
electric current value [kAT] from a source of electrical power
for magnetizing.
FIG. 23 is a graph showing a difference in magnitude of
electromagnetic forces in the radial direction among connection
15 patterns in the three-phase coils when the three-phase coils
are energized in the magnetization process of a magnetic
material.
FIG. 24 is a graph showing a difference in magnitude of
electromagnetic forces in the axial direction among connection
20 patterns in the three-phase coils when the three-phase coils
are energized in the magnetization process of a magnetic
material.
FIG. 25 is a graph showing a relationship between an
angle [degree] with respect to a reference position and an
25 electric current value [kAT] from a source of electrical power
for magnetizing.
FIG. 26 is a graph showing a difference in magnitude of
electromagnetic forces in the radial direction among connection
patterns in the three-phase coils when the three-phase coils
30 are energized in the magnetization process of a magnetic
material.
FIG. 27 is a graph showing a difference in magnitude of
electromagnetic forces in the axial direction among connection
patterns in the three-phase coils when the three-phase coils
8
are energized in the magnetization process of a magnetic
material.
FIG. 28 is a graph showing a difference in magnitude of
electromagnetic forces in the radial direction among connection
5 patterns in the three-phase coils when the three-phase coils
are energized in the magnetization process of a magnetic
material.
FIG. 29 is a graph showing a difference in magnitude of
electromagnetic forces in the axial direction among connection
10 patterns in the three-phase coils when the three-phase coils
are energized in the magnetization process of a magnetic
material.
FIG. 30 is a cross-sectional view schematically
illustrating a configuration of a compressor according to a
15 second embodiment of the present invention.
FIG. 31 is a diagram schematically illustrating a
configuration of a refrigeration air conditioning apparatus
according to a third embodiment of the present invention.
20 MODE FOR CARRYING OUT THE INVENTION
[0009]
FIRST EMBODIMENT
In xyz orthogonal coordinate systems illustrated in the
drawings, a z-axis direction (z axis) represents a direction
25 parallel to an axis line Ax of an electric motor rotor 1, an xaxis direction (x axis) represents a direction orthogonal to
the z-axis direction (z axis), and a y-axis direction (y axis)
represents a direction orthogonal to both the z-axis direction
and the x-axis direction. The axis line Ax is a center of a
30 stator 3, that is, a rotation center of a rotor 2. A direction
parallel to the axis line Ax will be referred to as an “axial
direction of the rotor 2” or simply as an “axial direction.” A
radial direction refers to a direction of a radius of the rotor
2 or the stator 3, and is a direction orthogonal to the axis
9
line Ax. An xy plane is a plane orthogonal to the axial
direction. An arrow D1 represents a circumferential direction
about the axis line Ax. The circumferential direction of the
rotor 2 or the stator 3 will be referred to simply as a
5 “circumferential direction.”
[0010]

FIG. 1 is a plan view schematically illustrating a
configuration of the electric motor 1 according to the first
10 embodiment of the present invention.
[0011]
The electric motor 1 includes the rotor 2 having a
plurality of magnetic poles, the stator 3, and a shaft 4 fixed
to the rotor 2. The electric motor 1 is, for example, a
15 permanent magnet synchronous motor.
[0012]
FIG. 2 is a plan view schematically illustrating a
configuration of the rotor 2.
The rotor 2 is rotatably disposed inside the stator 3.
20 The rotor 2 includes a rotor core 21 and at least one permanent
magnet 22 that is a magnetic material. An air gap is present
between the rotor 2 and the stator 3. The rotor 2 rotates
about the axis line Ax.
[0013]
25 The rotor core 21 includes a plurality of magnet
insertion holes 211 and a shaft hole 212. The rotor core 21
may further include at least one flux barrier that is space
communicating with the magnet insertion holes 211.
[0014]
30 In this embodiment, the rotor 2 includes a plurality of
permanent magnets 22. The permanent magnets 22 are
individually disposed in the magnet insertion holes 211. The
shaft 4 is fixed to the shaft hole 212.
[0015]
10
Each of the permanent magnets 22 included in the electric
motor 1 as a finished product is a magnetized magnetic material
22. In this embodiment, two adjacent permanent magnets 22 form
one magnetic pole, that is, a north pole or a south pole, of
5 the rotor 2. It should be noted that one permanent magnet 22
may form one magnetic pole of the rotor 2.
[0016]
In this embodiment, in the xy plane, a pair of permanent
magnets 22 forming one magnetic pole of the rotor 2 is disposed
10 to have a V shape. It should be noted that in the xy plane,
one pair of permanent magnets 22 forming one magnetic pole of
the rotor 2 may be disposed to be straight.
[0017]
The center of each magnetic pole of the rotor 2 is
15 located at the center of each magnetic pole of the rotor 2
(i.e., a north pole or a south pole of the rotor 2). Each of
the magnetic poles (also referred to simply as “each magnetic
pole” or a “magnetic pole”) of the rotor 2 means a region
serving as a north pole or a south pole of the rotor 2.
20 [0018]
The center of each magnetic pole of the rotor 2 is
indicated by a magnetic pole center line M1. In the example
illustrated in FIG. 2, the magnetic pole center line M1 passes
between two permanent magnets 22 forming one magnetic pole of
25 the rotor 2 and through the axis line Ax in the xy plane. That
is, in the example illustrated in FIG. 2, the center of each
magnetic pole of the rotor 2 includes a position between two
permanent magnets 22 forming one magnetic pole.
[0019]
30 In the case where one permanent magnet 22 forms one
magnetic pole of the rotor 2, the center of each magnetic pole
of the rotor 2 includes the center of one permanent magnet 22
in the xy plane. In this case, in the xy plane, the magnetic
pole center line M1 passes through the center of each permanent
11
magnet 22 and the axis line Ax.
[0020]

FIG. 3 is a plan view illustrating an example of the
5 stator 3.
FIG. 4 is a plan view schematically illustrating an
internal configuration of the stator 3 illustrated in FIG. 3.
[0021]
The stator 3 includes a stator core 31 and three-phase
10 coils 32.
[0022]
The stator core 31 includes a plurality of slots 311 in
which the three-phase coils 32 are disposed. In the example
illustrated in FIG. 3, the stator core 31 includes eighteen
15 slots 311.
[0023]
The three-phase coils 32 are wound around the stator core
31 by distributed winding. As illustrated in FIG. 4, the
three-phase coils 32 include coil sides 32b disposed in the
20 slots 311 and coil ends 32a not disposed in the slots 311. The
coil ends 32a are end portions of the three-phase coils 32 in
the axial direction.
[0024]
The three-phase coils 32 include at least one internal
25 phase coil 321, at least one intermediate phase coil 322, and
at least one external phase coil 323. That is, the three-phase
coils 32 have a first phase, a second phase, and a third phase.
For example, the first phase is a V phase, the second phase is
a W phase, and the third phase is a U phase. In this
30 embodiment, when an electric current flows through the threephase coils 32, the three-phase coils 32 form six magnetic
poles.
[0025]
In the example illustrated in FIG. 3, the three-phase
12
coils 32 have three internal phase coils 321, three
intermediate phase coils 322, and three external phase coils
323. The number of coils of each phase is not limited to three.
In this embodiment, the stator 3 has the configuration
5 illustrated in FIG. 3 at two coil ends 32a. It should be noted
that the stator 3 only needs to have the configuration
illustrated in FIG. 3 at one of the two coil ends 32a.
[0026]
In the coil ends 32a of the three-phase coils 32, the
10 first phase coil, the second phase coil, and the third phase
coil in each set of the three-phase coils 32 are arranged in
this order in the circumferential direction of the stator core
31. In the example illustrated in FIG. 3, in the coil ends 32a
of the three-phase coils 32, the intermediate phase coil 322,
15 the internal phase coil 321, and the external phase coil 323 in
each set of the three-phase coils 32 are arranged in this order
in the circumferential direction of the stator core 31. In the
coil ends 32a, coils of the individual phases are arranged at
regular intervals in the circumferential direction. The coil
20 of any one of the phases is disposed in one slot 311.
Accordingly, magnetic flux of the permanent magnets 22 of the
rotor 2 can be effectively used.
[0027]
As illustrated in FIG. 3, in the coil ends 32a of the
25 three-phase coils 32, the internal phase coils 321 are located
closer to the center of the stator core 31 than the external
phase coils 323 are. In this case, for example, the first
phase coils are the intermediate phase coils 322, the second
phase coils are the internal phase coils 321, and the third
30 phase coils are the external phase coils 323.
[0028]
It should be noted that in the coil ends 32a of the
three-phase coils 32, the second phase coil, the first phase
coil, and the third phase coil in each set may be arranged in
13
this order in the circumferential direction of the stator core
31. In this case, in the coil ends 32a, the first phase coils
are located closer to the center of the stator core 31 than the
third phase coils are.
5 [0029]
FIG. 5 is a schematic diagram illustrating an example of
connection in the three-phase coils 32.
A connection in the three-phase coils 32 is, for example,
Y-connection. In other words, the three-phase coils 32 are
10 connected by, for example, Y-connection. In this case, the
internal phase coil 321, the intermediate phase coil 322, and
the external phase coil 323 are connected by Y-connection.
[0030]
FIGS. 6 through 11 are diagrams illustrating examples of
15 a connection pattern of the three-phase coils 32 in magnetizing
an unmagnetized magnetic material 22 by using the stator 3. In
other words, FIGS. 6 through 11 are diagrams illustrating an
example of a connection state between the three-phase coils 32
connected by Y-connection and a source of electrical power for
20 magnetizing. Arrows in FIGS. 6 through 11 represent directions
of electric currents. The source of electrical power for
magnetizing will also be referred to simply as a “source of
electrical power.” In this embodiment, the source of
electrical power is a direct current power source.
25 [0031]
In the example illustrated in FIG. 6, a positive side of
the source of electrical power (i.e., a positive pole side of
the source of electrical power) is connected to the
intermediate phase coil 322, and a negative side of the source
30 of electrical power (i.e., a negative pole side of the source
of electrical power) is connected to the internal phase coil
321 and the external phase coil 323. The connection state
illustrated in FIG. 6 will be referred to as a connection
pattern P1. In this case, a large electric current flows from
14
the source of electrical power to the intermediate phase coil
322. The electric current flowing from the source of
electrical power to the intermediate phase coil 322 is divided
into an electric current flowing through the internal phase
5 coil 321 and an electric current flowing through the external
phase coil 323. Thus, the electric current flowing through the
intermediate phase coil 322 is larger than each of the electric
current flowing through the internal phase coil 321 and the
electric current flowing through the external phase coil 323.
10 [0032]
In the example illustrated in FIG. 7, the positive side
of the source of electrical power is connected to the internal
phase coil 321, and the negative side of the source of
electrical power is connected to the intermediate phase coil
15 322 and the external phase coil 323. The connection state
illustrated in FIG. 7 will be referred to as a connection
pattern P2. In this case, a large electric current flows from
the source of electrical power to the internal phase coil 321.
The electric current flowing from the source of electrical
20 power to the internal phase coil 321 is divided into the
electric current flowing through the intermediate phase coil
322 and the electric current flowing through the external phase
coil 323. Thus, the electric current flowing through the
internal phase coil 321 is larger than each of the electric
25 current flowing through the intermediate phase coil 322 and the
electric current flowing through the external phase coil 323.
[0033]
In the example illustrated in FIG. 8, the positive side
of the source of electrical power is connected to the external
30 phase coil 323, and the negative side of the source of
electrical power is connected to the internal phase coil 321
and the intermediate phase coil 322. The connection state
illustrated in FIG. 8 will be referred to as a connection
pattern P3. In this case, a large electric current flows from
15
the source of electrical power to the external phase coil 323.
The electric current flowing from the source of electrical
power to the external phase coil 323 is divided into an
electric current flowing through the internal phase coil 321
5 and an electric current flowing through the intermediate phase
coil 322. Thus, the electric current flowing through the
external phase coil 323 is larger than each of the electric
current flowing through the internal phase coil 321 and the
electric current flowing through the intermediate phase coil
10 322.
[0034]
In the example illustrated in FIG. 9, the positive side
of the source of electrical power is connected to the
intermediate phase coil 322, and the negative side of the
15 source of electrical power is connected to the internal phase
coil 321. One end of the external phase coil 323 is an open
end. The connection state illustrated in FIG. 9 will be
referred to as a connection pattern P4. In this case, a large
electric current flows from the source of electrical power to
20 the intermediate phase coil 322. The electric current flowing
from the source of electrical power to the intermediate phase
coil 322 flows through the internal phase coil 321 and does not
flow in the external phase coil 323.
[0035]
25 In the example illustrated in FIG. 10, the positive side
of the source of electrical power is connected to the internal
phase coil 321, and the negative side of the source of
electrical power is connected to the external phase coil 323.
One end of the intermediate phase coil 322 is an open end. The
30 connection state illustrated in FIG. 10 will be referred to as
a connection pattern P5. In this case, a large electric
current flows from the source of electrical power to the
internal phase coil 321. The electric current flowing from the
source of electrical power to the internal phase coil 321 flows
16
through the external phase coil 323 and does not flow in the
intermediate phase coil 322.
[0036]
In the example illustrated in FIG. 11, the positive side
5 of the source of electrical power is connected to the external
phase coil 323, and the negative side of the source of
electrical power is connected to the intermediate phase coil
322. One end of the internal phase coil 321 is an open end.
The connection state illustrated in FIG. 11 will be referred to
10 as a connection pattern P6. In this case, a large electric
current flows from the source of electrical power to the
external phase coil 323. The electric current flowing from the
source of electrical power to the external phase coil 323 flows
through the intermediate phase coil 322 and does not flow in
15 the internal phase coil 321.
[0037]

An example of a method for producing the stator 3 will be
described.
20 FIG. 12 is a flowchart depicting an example of a process
of producing the electric motor 1.
[0038]
In step S1, the rotor 2 is produced. Specifically, an
unmagnetized magnetic material 22 is placed in each magnet
25 insertion hole 211 of the rotor core 21. In step S1, the shaft
4 may be fixed to the shaft hole 212.
[0039]
In step S2, the three-phase coils 32 are attached to the
stator core 31. In this embodiment, the three-phase coils 32
30 are attached to the stator core 31 by distributed winding.
[0040]
In step S3, the internal phase coil 321, the intermediate
phase coil 322, and the external phase coil 323 are connected.
For example, the internal phase coil 321, the intermediate
17
phase coil 322, and the external phase coil 323 are connected
by Y-connection.
[0041]
It should be noted that the internal phase coil 321, the
5 intermediate phase coil 322, and the external phase coil 323
may be connected before the three-phase coils 32 are attached
to the stator core 31 by distributed winding. In this case, in
step S2, the internal phase coil 321, the intermediate phase
coil 322, and the external phase coil 323 connected to one
10 another may be attached to the stator core 31 by distributed
winding.
[0042]
In step S4, the rotor 2 having the unmagnetized magnetic
material 22 is disposed inside the stator 3 (specifically, the
15 stator core 31).
[0043]
FIG. 13 is a diagram illustrating an example of a process
of producing the electric motor 1.
In step S4, as illustrated FIG. 13, for example, the
20 rotor 2 is disposed at a reference position. The reference
position is a position at which the center of a magnetic pole
as a magnetization target of the rotor 2 indicated by the
magnetic pole center line M1 coincides with the center of the
magnetic pole of the coil connected to the positive side of the
25 source of electrical power (the first phase coil or the second
phase coil in this embodiment), in the xy plane.
[0044]
In the example illustrated in FIG. 13, the first phase
coil is an intermediate phase coil 322. The center of the
30 magnetic pole of the coil of each phase is the center of a
magnetic pole formed when an electric current flows through the
three-phase coils 32. In FIG. 13, the center of the magnetic
pole of the intermediate phase coil 322 is indicated by the
magnetic pole center line C1. In the xy plane, the magnetic
18
pole center line C1 passes through the axis line Ax and the
center of the magnetic pole of the first phase coil formed when
an electric current flows through the three-phase coils 32.
Specifically, in the example illustrated in FIG. 13, the center
5 of the magnetic pole of the intermediate phase coil 322 is the
center of the magnetic pole of the intermediate phase coil 322
formed when an electric current flows from the source of
electrical power to the intermediate phase coil 322.
[0045]
10 In step S5, the three-phase coils 32 are connected to the
source of electrical power for magnetizing. In step S5, the
connection state between the three-phase coils 32 and the
source of electrical power is a first connection state. The
first connection state is the connection state illustrated in
15 FIG. 6, the connection state illustrated in FIG. 7, the
connection state illustrated in FIG. 8, the connection state
illustrated in FIG. 9, the connection state illustrated in FIG.
10, or the connection state illustrated in FIG. 11. The coil
connected to the positive side of the source of electrical
20 power in the first connection state will be referred to as a
“first phase coil.”
[0046]
For example, in the examples illustrated in FIGS. 6 and 9,
the intermediate phase coil 322 of the three-phase coils 32 is
25 connected to the positive side of the source of electrical
power. In this case, the intermediate phase coil 322 will be
referred to as the “first phase coil.”
[0047]
In the examples illustrated in FIGS. 7 and 10, the
30 internal phase coil 321 of the three-phase coils 32 is
connected to the positive side of the source of electrical
power. In this case, the internal phase coil 321 will be
referred to as the “first phase coil.”
[0048]
19
In the examples illustrated in FIGS. 8 and 11, the
external phase coil 323 of the three-phase coils 32 is
connected to the positive side of the source of electrical
power. In this case, the external phase coil 323 will be
5 referred to as the “first phase coil.”
[0049]
In this embodiment, the first connection state is the
connection state illustrated in FIG. 6 or 9. That is, in this
embodiment, in step S5, the intermediate phase coil 322 is
10 connected to the positive side of the source of electrical
power.
[0050]
The order of process steps from step S2 to step S5 is not
limited to the example shown in FIG. 12 and may be changed when
15 necessary.
[0051]
FIG. 14 is a diagram illustrating an example of a process
of producing the electric motor 1, specifically, a first
magnetization process.
20 In step S6, an electric current is caused to flow in the
three-phase coils 32 in a state where the center of the
magnetic pole of the rotor 2 having the unmagnetized magnetic
material 22 is rotated a first angle θ1 with respect to the
center of the magnetic pole of the first phase coil in a first
25 rotation direction of the rotor 2. In the example illustrated
in FIG. 14, the first phase coil is the intermediate phase coil
322. That is, an electric current is caused to flow in the
three-phase coils 32 in a state where the center of the
magnetic pole of the rotor 2 is rotated the first angle θ1 from
30 the reference position in the first rotation direction of the
rotor 2. In other words, in the first connection state, an
electric current is caused to flow from the source of
electrical power to the three-phase coils 32 (specifically, the
first phase coil). In this embodiment, the first rotation
20
direction is a counterclockwise direction about the axis line
Ax.
[0052]
The direction of magnetic flux from the first phase coil
5 (the intermediate phase coil 322 in FIG. 14) is preferably as
parallel as possible to a magnetization facilitating direction
at one end side of the magnetic material 22 as a magnetization
target. Accordingly, this end side of the magnetic material 22
can be easily magnetized in the magnetization facilitating
10 direction without using a large electric current.
[0053]
Thus, the first angle θ1 is preferably an angle at which
the direction of magnetic flux from the first phase coil (the
intermediate phase coil 322 in FIG. 14) and the magnetization
15 facilitating direction of the magnetic material 22 as a
magnetization target form an angle near parallel. The first
angle θ1 is preferably an angle at which the direction of
magnetic flux from the first phase coil (the intermediate phase
coil 322 in FIG. 14) is parallel to the magnetization
20 facilitating direction of the magnetic material 22 as a
magnetization target.
[0054]
While the first connection state is in the connection
state illustrated in FIG. 6, 7, or 8, an electric current
25 flowing from the source of electrical power to the first phase
coil is divided into an electric current flowing through the
second phase coil and an electric current flowing through the
third phase coil. That is, the electric current flows through
the coils of the individual phases, that is, the first phase
30 coil, the second phase coil, and the third phase coil. In this
case, the first angle θ1 satisfies 0 degrees < θ1 ≤ 10 degrees,
for example.
[0055]
On the other hand, while the first connection state is in
21
the connection state illustrated in FIG. 9, 10, or 11, an
electric current flowing from the source of electrical power to
the first phase coil flows through the second phase coil or the
third phase coil and does not flow through one of the second
5 phase coil or the third phase coil. That is, the electric
current flows only through two of the three phases, and does
not flow through one of the three phases. In this case, the
first angle θ1 satisfies 2.5 degrees ≤ θ1 ≤ 12.5 degrees, for
example.
10 [0056]
In the first connection state, when an electric current
flows from the source of electrical power to the three-phase
coils 32, magnetic flux occurs from the three-phase coils 32,
and the magnetic material 22 as a magnetization target is
15 magnetized in a direction Md indicated by arrows. The
direction Md is the magnetization facilitating direction of the
magnetic material 22. Since the rotor 2 is in the state in
which the rotor 2 is rotated the first angle θ1 with respect to
the center of the magnetic pole of the first phase coil (the
20 intermediate phase coil 322 in FIG. 14), the magnetic material
22 can be easily magnetized in the magnetization facilitating
direction of the magnetic material 22. In this embodiment, the
magnetization facilitating direction of the magnetic material
22 is a lateral direction of the magnetic material 22 in the xy
25 plane.
[0057]
As described above, in this embodiment, two permanent
magnets 22 form one magnetic pole of the rotor 2, but one
permanent magnet 22 may form one magnetic pole of the rotor 2.
30 In this case, two magnetic materials 22 illustrated in FIG. 14
are united as one member.
[0058]
In step S7, connection of the three-phase coils 32 is
switched. Specifically, connection to the positive side of the
22
source of electrical power is switched from the first phase
coil to the second phase coil of the three-phase coils 32. In
the state where the first phase coil is the intermediate phase
coil 322, the second phase coil is the internal phase coil 321
5 or the external phase coil 323. Accordingly, an
electrification path in the three-phase coils 32 is changed.
[0059]
In step S7, the connection state between the three-phase
coils 32 and the source of electrical power is a second
10 connection state different from the first connection state.
That is, in step S7, the connection state of the three-phase
coils 32 is switched from the first connection state to the
second connection state. The second connection state is the
connection state illustrated in FIG. 6, the connection state
15 illustrated in FIG. 7, the connection state illustrated in FIG.
8, the connection state illustrated in FIG. 9, the connection
state illustrated in FIG. 10, or the connection state
illustrated in FIG. 11. The coil connected to the positive
side of the source of electrical power in the second connection
20 state will be referred to as a “second phase coil.”
[0060]
In this embodiment, the second connection state is the
connection state illustrated in FIG. 7. That is, in this
embodiment, connection to the positive side of the source of
25 electrical power is switched from the intermediate phase coil
322 to the second phase coil (the internal phase coil 321 in
this embodiment) of the three-phase coils 32 (step S7).
[0061]
FIG. 15 is a diagram illustrating an example of a process
30 of producing the electric motor 1, specifically, a second
magnetization process.
In step S8, an electric current is caused to flow through
the three-phase coils 32 in a state where the center of the
magnetic pole of the rotor 2 is rotated a second angle θ2 in a
23
second rotation direction of the rotor 2 with respect to the
center of the magnetic pole of the second phase coil formed
when an electric current flows from the source of electrical
power to the second phase coil. In the example illustrated in
5 FIG. 15, the second phase coil is the internal phase coil 321.
The second rotation direction is an opposite direction to the
first rotation direction. That is, an electric current is
caused to flow through the three-phase coils 32 in a state
where the center of the magnetic pole of the rotor 2 is rotated
10 the second angle θ2 from the reference position in the second
rotation direction of the rotor 2. In other words, in the
second connection state, an electric current is caused to flow
from the source of electrical power to the three-phase coils 32
(specifically, the second phase coil).
15 [0062]
In the second connection state, the reference position is
a position at which the center of a magnetic pole as a
magnetization target of the rotor 2 indicated by the magnetic
pole center line M1 coincides with the center of the magnetic
20 pole of the second phase coil (the internal phase coil 321 in
FIG. 15).
[0063]
In this embodiment, the second rotation direction is a
clockwise direction about the axis line Ax. The second
25 rotation direction may be a counterclockwise direction about
the axis line Ax. In this case, the first rotation direction
is a clockwise direction.
[0064]
In FIG. 15, the center of the magnetic pole of the
30 internal phase coil 321 is indicated by a magnetic pole center
line C2. The magnetic pole center line C2 passes through the
center of the magnetic pole of the second phase coil formed
when an electric current flows through the three-phase coils 32.
Specifically, in the example illustrated in FIG. 15, the center
24
of the magnetic pole of the internal phase coil 321 is the
center of the magnetic pole of the internal phase coil 321
formed when an electric current flows from the source of
electrical power to the internal phase coil 321.
5 [0065]
The direction of magnetic flux from the second phase coil
(the internal phase coil 321 in FIG. 15) is preferably as
parallel as possible to a magnetization facilitating direction
at the other end side of the magnetic material 22 as a
10 magnetization target. Accordingly, this end side of the
magnetic material 22 can be easily magnetized in the
magnetization facilitating direction without using a large
electric current.
[0066]
15 Thus, the second angle θ2 is preferably an angle at which
the direction of magnetic flux from the second phase coil (the
internal phase coil 321 in FIG. 15) and the magnetization
facilitating direction of the magnetic material 22 as a
magnetization target form an angle near parallel. The second
20 angle θ2 is more preferably an angle at which the direction of
magnetic flux from the second phase coil (the internal phase
coil 321 in FIG. 15) is parallel to the magnetization
facilitating direction of the magnetic material 22 as a
magnetization target.
25 [0067]
While the second connection state is in the connection
state illustrated in FIG. 6, 7, or 8, an electric current
flowing from the source of electrical power to the second phase
coil is divided into an electric current flowing through the
30 first phase coil and an electric current flowing through the
third phase coil. That is, the electric current flows through
the coils of the individual phases, that is, the first phase
coil, the second phase coil, and the third phase coil. In this
case, the second angle θ2 satisfies 0 degrees < θ2 ≤ 10 degrees,
25
for example.
[0068]
On the other hand, while the second connection state is
in the connection state illustrated in FIG. 9, 10, or 11, an
5 electric current flowing from the source of electrical power to
the second phase coil flows through the first phase coil or the
third phase coil and does not flow through one of the first
phase coil or the third phase coil. That is, the electric
current flows only through two of the three phases, and does
10 not flow through one of the three phases. In this case, the
second angle θ2 satisfies 2.5 degrees ≤ θ1 ≤ 12.5 degrees, for
example.
[0069]
In the second connection state, when an electric current
15 flows from the source of electrical power to the three-phase
coils 32, magnetic flux occurs from the three-phase coils 32,
and the magnetic material 22 as a magnetization target is
magnetized in the direction Md indicated by arrows. Since the
rotor 2 is in the state in which the rotor 2 is rotated the
20 second angle θ2 with respect to the center of the magnetic pole
of the second phase coil (the internal phase coil 321 in FIG.
15), the magnetic material 22 can be easily magnetized in the
magnetization facilitating direction of the magnetic material
22.
25 [0070]
In step S9, the three-phase coils 32 are detached from
the source of electrical power. In this manner, the electric
motor 1 is obtained.
[0071]
30 In this embodiment, the first phase coil is the
intermediate phase coil 322, the second phase coil is the
internal phase coil 321, and the third phase coil is the
external phase coil 323, but the first phase coil is not
limited to the intermediate phase coil 322, the second phase
26
coil is not limited to the internal phase coil 321, and the
third phase coil is not limited to the external phase coil 323.
For example, the first phase coil may be the internal phase
coil 321, the second phase coil may be the intermediate phase
5 coil 322, and the third phase coil may be the external phase
coil 323.
[0072]

FIG. 16 is a diagram illustrating another example of the
10 stator 3.
In the stator 3 illustrated in FIG. 16, the number of
first phase coils is equal to the number of magnetic poles of
the rotor 2, the number of second phase coils is equal to the
number of magnetic poles of the rotor 2, and the number of
15 third phase coils is equal to the number of magnetic poles of
the rotor 2. That is, the three-phase coils 32 include six
internal phase coils 321, six intermediate phase coils 322, and
six external phase coils 323.
[0073]
20 In the stator 3 illustrated in FIG. 16, in the coil ends
32a of the three-phase coils 32, coils of each phase in the
three-phase coils 32 have a ring shape. Specifically, in the
coil ends 32a of the three-phase coils 32, the six internal
phase coils 321 have a ring shape, the six intermediate phase
25 coils 322 have a ring shape, and the six external phase coils
323 have a ring shape.
[0074]
In the stator 3 illustrated in FIG. 16, in the coil ends
32a of the three-phase coils 32, coils of each phase in the
30 three-phase coils 32 are concentrically arranged. Specifically,
in the coil ends 32a of the three-phase coils 32, the six
internal phase coils 321 are concentrically arranged, the six
intermediate phase coils 322 are concentrically arranged, and
the six external phase coils 323 are concentrically arranged.
27
[0075]
In each slot 311, adjacent coils of the same phase are
disposed.
[0076]
5 For example, in the coil ends 32a of the three-phase
coils 32, in the radial direction of the stator core 31, the
first phase coils are located outside the second phase coils,
and the third phase coils are located outside the first phase
coils. In the example illustrated in FIG. 16, the first phase
10 coils are the intermediate phase coils 322, the second phase
coils are the internal phase coils 321, and the third phase
coils are the external phase coil 323.
[0077]
In the coil ends 32a of the three-phase coils 32, in the
15 radial direction of the stator core 31, the second phase coils
may be located outside the first phase coils, and the third
phase coils may be located outside the second phase coils.
[0078]
The stator 3 illustrated in FIG. 16 is applicable to the
20 electric motor 1 described above. A method for producing the
electric motor 1 including the stator 3 illustrated in FIG. 16
is the same as the method described in .
[0079]
25
Advantages of the method for producing the electric motor
1 will be described.
FIG. 17 is a diagram illustrating a magnetization process
in an electric motor as a comparative example.
30 In the example illustrated in FIG. 17, in a magnetization
process, an angle with respect to a reference position is zero.
In this case, the direction of magnetic flux from three-phase
coils (the intermediate phase coils 322 in FIG. 17) is close to
a right angle with respect to a magnetization facilitating
28
direction of a magnetic material 22 as a magnetization target.
Thus, in the example illustrated in FIG. 17, it is difficult to
magnetize both ends of the magnetic material 22 in the xy plane
in the magnetization facilitating direction.
5 [0080]
On the other hand, in this embodiment, magnetization is
performed twice on each magnetic pole of the rotor 2.
Specifically, first magnetization is performed in a state where
the center of the magnetic pole of the rotor 2 is rotated the
10 first angle θ1 with respect to the center of the magnetic pole
of the first phase coil for each magnetic pole of the rotor 2.
Accordingly, the magnetic material 22 can be magnetized in a
state where the direction of magnetic flux from the first phase
coil is as parallel as possible to the magnetization
15 facilitating direction at one end side of the magnetic material
22 as a magnetization target. In particular, one end side of
the magnetic material 22 in the xy plane is easily magnetized
in the magnetization facilitating direction.
[0081]
20 Thereafter, second magnetization is performed in a state
where the center of the magnetic pole of the rotor 2 is rotated
the second angle θ2 with respect to the center of the magnetic
pole of the second phase coil in a second rotation direction R2
of the rotor 2 for each magnetic pole of the rotor 2.
25 Accordingly, the magnetic material 22 can be magnetized in a
state where the direction of magnetic flux from the second
phase coil is as parallel as possible to the magnetization
facilitating direction at the other end side of the magnetic
material 22 as a magnetization target. As a result, the
30 magnetic material 22 can be easily magnetized in the
magnetization facilitating direction without using a large
electric current. In particular, the other end side of the
magnetic material 22 in the xy plane is easily magnetized in
the magnetization facilitating direction. Accordingly, an
29
electric current for magnetization can be reduced, as compared
to the example illustrated in FIG. 17.
[0082]
In addition, since the magnetic material 22 can be easily
5 magnetized in the magnetization facilitating direction, a
magnetic force of the rotor 2 can be enhanced. As a result,
the highly efficient electric motor 1 can be provided.
[0083]
In this embodiment, however, since magnetization is
10 performed twice on the magnetic pole as a magnetization target
of the rotor 2, a large force is generated in the three-phase
coils 32, and the coil ends 32a of the three-phase coils 32 are
more likely to be deformed than the example illustrated in FIG.
17.
15 [0084]
FIG. 18 is a diagram illustrating an example of
electromagnetic forces F1 in the radial direction generated in
the coil ends 32a of the three-phase coils 32 when the threephase coils 32 are energized in a process of producing the
20 electric motor 1, specifically, the magnetization process of
the magnetic material 22. In FIG. 18, arrows in the threephase coils 32 represent directions of an electric current.
FIG. 19 is a diagram illustrating an example of
electromagnetic forces F2 in the axial direction generated in
25 the coil ends 32a of the three-phase coils 32 when the threephase coils 32 are energized in the process of producing the
electric motor 1, specifically, the magnetization process of
the magnetic material 22.
[0085]
30 In the example illustrated in FIG. 18, when an electric
current flows from the source of electrical power for
magnetizing to the three-phase coils 32, electromagnetic forces
F1 that repel each other in the radial direction are generated
between the internal phase coil 321 and the intermediate phase
30
coil 322, and electromagnetic forces F1 that repel each other
in the radial direction are generated between the internal
phase coil 321 and the external phase coil 323. In addition,
as illustrated in FIG. 19, electromagnetic forces F2 in the
5 axial direction are generated in the three-phase coils 32.
[0086]
FIG. 20 is a graph showing a difference in magnitude of
electromagnetic forces F1 in the radial direction among
connection patterns in the three-phase coils 32 when the three10 phase coils 32 are energized in the magnetization process of
the magnetic material 22. Data shown in FIG. 20 is an analysis
result of an electromagnetic field analysis. In FIG. 20, the
connection patterns P1, P2, and P3 respectively correspond to
connection patterns illustrated in FIGS. 6 through 8.
15 [0087]
In the connection pattern P3, a large electric current
flows from the source of electrical power for magnetizing to
the external phase coil 323, and the electric current flowing
through the external phase coil 323 is larger than each of an
20 electric current flowing through the internal phase coil 321
and an electric current flowing through the intermediate phase
coil 322. In this case, as shown in FIG. 20, the
electromagnetic force F1 generated in the external phase coil
323 is significantly larger than the electromagnetic forces F1
25 generated in the other coils. Accordingly, the external phase
coil 323 is likely to be deformed in the radial direction. In
this case, when the electric motor 1 is applied to a compressor,
for example, the external phase coil 323 is located close to a
metal part (e.g., a closed container of the compressor), and it
30 is difficult to obtain electrical insulation of the external
phase coil 323.
[0088]
On the other hand, in the connection pattern P1, a large
electric current flows from the source of electrical power for
31
magnetizing to the intermediate phase coil 322, and the
electric current flowing through the intermediate phase coil
322 is larger than each of an electric current flowing through
the internal phase coil 321 and an electric current flowing
5 through the external phase coil 323. In the connection pattern
P1, there is no significant difference among the
electromagnetic forces F1 generated in the coils of the
individual phases. In particular, the electromagnetic force F1
generated in the external phase coil 323 is smaller than the
10 electromagnetic forces F1 generated in the other coils.
Accordingly, in performing magnetization with the rotor 2
disposed inside the stator 3, significant deformation of the
three-phase coils 32, especially the external phase coil 323,
can be prevented. In addition, since deformation of the
15 external phase coil 323 is suppressed, electrical insulation of
the external phase coil 323 can be obtained.
[0089]
In the connection pattern P2, a large electric current
flows from the source of electrical power for magnetizing to
20 the internal phase coil 321, and the electric current flowing
through the internal phase coil 321 is larger than each of an
electric current flowing through the intermediate phase coil
322 and an electric current flowing through the external phase
coil 323. In the connection pattern P1, especially the
25 electromagnetic force F1 generated in the external phase coil
323 is smaller than the electromagnetic forces F1 generated in
the other coils. Accordingly, in performing magnetization with
the rotor 2 disposed inside the stator 3, significant
deformation of the three-phase coils 32, especially the
30 external phase coil 323, can be prevented. In addition, since
deformation of the external phase coil 323 is suppressed,
electrical insulation of the external phase coil 323 can be
obtained.
[0090]
32
FIG. 21 is a graph showing a difference in magnitude of
electromagnetic forces F2 in the axial direction among
connection patterns in the three-phase coils 32 when the threephase coils 32 are energized in the magnetization process of
5 the magnetic material 22. In FIG. 21, the connection patterns
P1, P2, and P3 respectively correspond to the connection
patterns P1, P2, and P3 in FIG. 20.
[0091]
As illustrated in FIG. 21, with respect to
10 electromagnetic forces F2 in the axial direction, a large
electromagnetic force F2 in the axial direction is generated in
one of the three-phase coils 32 irrespective of connection
pattern. Specifically, in the connection pattern P3, a large
electric current flows from the source of electrical power to
15 the external phase coil 323, and a large electromagnetic force
F2 in the axial direction is generated in the external phase
coil 323. In the connection pattern P1, a large electric
current flows from the source of electrical power to the
intermediate phase coil 322, and a large electromagnetic force
20 F2 in the axial direction is generated in the intermediate
phase coil 322. In the connection pattern P2, a large electric
current flows from the source of electrical power to the
internal phase coil 321, and a large electromagnetic force F2
in the axial direction is generated in the internal phase coil
25 321.
[0092]
Regarding deformation of the three-phase coils 32 in the
axial direction, influence on performance of the electric motor
1 is smaller than that in deformation of the three-phase coils
30 32 in the radial direction. Thus, in the magnetization process
of the magnetic material 22, the first connection state is
preferably the connection pattern P1 or P2, and similarly, the
second connection state is preferably the connection pattern P1
or P2. That is, in a case where the first connection state is
33
the connection pattern P1, the second connection state is the
connection pattern P2. In a case where the second connection
state is the connection pattern P2, the second connection state
is the connection pattern P1.
5 [0093]
Accordingly, in performing magnetization with the rotor 2
disposed inside the stator 3, significant deformation of the
three-phase coils 32, especially the external phase coil 323,
can be prevented. In addition, since deformation of the
10 external phase coil 323 is suppressed, performance of the
electric motor 1, such as electrical insulation of the external
phase coil 323, can be obtained.
[0094]
FIG. 22 is a graph showing a relationship between an
15 angle [degree] with respect to a reference position in the
connection pattern P1 or P2 and an electric current value [kAT]
from the source of electrical power for magnetizing. In FIG.
22, the angle with respect to the reference position
corresponds to the first angle θ1 and the second angle θ2
20 described above.
[0095]
As shown in FIG. 22, if the angle with respect to the
reference position is zero, an electric current value from the
source of electrical power for magnetizing is 278 [kAT]. On
25 the other hand, in this embodiment, if the first connection
state and the second connection state is the connection pattern
P1 or P2, the first angle θ1 and the second angle θ2 satisfy 0
degrees < θ1 ≤ 10 degrees, and 0 degrees < θ2 ≤ 10 degrees.
Accordingly, the electric current from the source of electrical
30 power for magnetizing can be reduced, as compared to a
conventional magnetization method. The first angle θ1 and the
second angle θ2 more preferably satisfy 2.5 degrees ≤ θ1 ≤ 10
degrees, and 2.5 degrees ≤ θ2 ≤ 10 degrees. The first angle θ1
more preferably satisfies 2.5 degrees ≤ θ1 ≤ 7.5 degrees or 5
34
degrees ≤ θ1 ≤ 10 degrees. In the example illustrated in FIG.
22, the first angle θ1 and the second angle θ2 are most
preferably 5 degrees. In this case, the electric current value
is reduced by about 20.5%, as compared to the conventional
5 magnetization method.
[0096]
FIG. 23 is a graph showing a difference in magnitude of
electromagnetic forces F1 in the radial direction among
connection patterns in the three-phase coils 32 when the three10 phase coils 32 are energized in the magnetization process of
the magnetic material 22. Data shown in FIG. 23 is an analysis
result of an electromagnetic field analysis. In FIG. 23, the
connection patterns P4, P5, and P6 respectively correspond to
connection patterns illustrated in FIGS. 9 through 11.
15 [0097]
In the connection pattern P6, a large electric current
flows from the source of electrical power for magnetizing to
the external phase coil 323. In this case, as shown in FIG. 23,
the electromagnetic force F1 generated in the external phase
20 coil 323 is significantly larger than the electromagnetic
forces F1 generated in the other coils. Accordingly, the
external phase coil 323 is likely to be deformed in the radial
direction. In this case, when the electric motor 1 is applied
to a compressor, for example, the external phase coil 323 is
25 located close to a metal part (e.g., a closed container of the
compressor), and it is difficult to obtain electrical
insulation of the external phase coil 323.
[0098]
On the other hand, in the connection pattern P4, a large
30 electric current flows from the source of electrical power for
magnetizing to the intermediate phase coil 322. In the
connection pattern P4, there is no significant difference among
the electromagnetic forces F1 generated in the coils of the
individual phases where electric currents flow. In particular,
35
no electromagnetic force F1 is generated in the external phase
coil 323. Accordingly, in performing magnetization with the
rotor 2 disposed inside the stator 3, significant deformation
of the three-phase coils 32, especially the external phase coil
5 323, can be prevented. In addition, since deformation of the
external phase coil 323 is suppressed, electrical insulation of
the external phase coil 323 can be obtained.
[0099]
FIG. 24 is a graph showing a difference in magnitude of
10 electromagnetic forces F2 in the axial direction among
connection patterns in the three-phase coils 32 when the threephase coils 32 are energized in the magnetization process of
the magnetic material 22. In FIG. 24, the connection patterns
P4, P5, and P6 respectively correspond to the connection
15 patterns P4, P5, and P6 in FIG. 23.
[0100]
As illustrated in FIG. 24, with respect to
electromagnetic forces F2 in the axial direction, a large
electromagnetic force F2 in the axial direction is generated in
20 one of the three-phase coils 32 irrespective of connection
pattern.
[0101]
Regarding deformation of the three-phase coils 32 in the
axial direction, influence on performance of the electric motor
25 1 is smaller than that in deformation of the three-phase coils
32 in the radial direction. Thus, in the magnetization process
of the magnetic material 22, the first connection state is
preferably the connection pattern P4 or P5, and similarly, the
second connection state is preferably the connection pattern P4
30 or P5. That is, in a case where the first connection state is
the connection pattern P4, the second connection state is the
connection pattern P5. In a case where the second connection
state is the connection pattern P5, the second connection state
is the connection pattern P4.
36
[0102]
Accordingly, in performing magnetization with the rotor 2
disposed inside the stator 3, significant deformation of the
three-phase coils 32, especially the external phase coil 323,
5 can be prevented. In addition, since deformation of the
external phase coil 323 is suppressed, performance of the
electric motor 1, such as electrical insulation of the external
phase coil 323, can be obtained.
[0103]
10 FIG. 25 is a graph showing a relationship between an
angle [degree] with respect to the reference position in the
connection pattern P4 or P5 and an electric current value [kAT]
from the source of electrical power for magnetizing. In FIG.
25, the angle with respect to the reference position
15 corresponds to the first angle θ1 and the second angle θ2
described above.
[0104]
As shown in FIG. 25, if the angle with respect to the
reference position is zero, an electric current value from the
20 source of electrical power for magnetizing is 450 [kAT]. On
the other hand, in this embodiment, if the first connection
state and the second connection state are the connection
pattern P4 or P5, the first angle θ1 and the second angle θ2
satisfy 0 degrees < θ1 ≤ 12.5 degrees, and 0 degrees < θ2 ≤
25 12.5 degrees. Accordingly, the electric current from the
source of electrical power for magnetizing can be reduced, as
compared to a conventional magnetization method. The first
angle θ1 and the second angle θ2 more preferably satisfy 2.5
degrees ≤ θ1 ≤ 12.5 degrees, and 2.5 degrees ≤ θ2 ≤ 12.5
30 degrees. The first angle θ1 and the second angle θ2 more
preferably satisfy 5 degrees ≤ θ1 ≤ 12.5 degrees, and 5 degrees
≤ θ2 ≤ 12.5 degrees. The first angle θ1 and the second angle
θ2 more preferably satisfy 5 degrees ≤ θ1 ≤ 10 degrees, and 5
degrees ≤ θ2 ≤ 10 degrees. In the example shown in FIG. 25,
37
the first angle θ1 and the second angle θ2 are most preferably
7.5 degrees. In this case, the electric current value is
reduced by 53.3%, as compared to the conventional magnetization
method.
5 [0105]
In addition, in the connection pattern P4 or P5, the
electric current from the source of electrical power for
magnetizing can be reduced to 210 [kAT]. Thus, in the
connection pattern P4 or P5, the electric current from the
10 source of electrical power for magnetizing can be reduced
compared with the minimum value 221 [kAT] in the connection
pattern P1 or P2.
[0106]
FIG. 26 is a graph showing a difference in magnitude of
15 electromagnetic forces F1 in the radial direction among
connection patterns in the three-phase coils 32 when the threephase coils 32 are energized in a magnetization process of the
magnetic material 22 according to the variation illustrated in
FIG. 16. Data shown in FIG. 26 is an analysis result of an
20 electromagnetic field analysis. In FIG. 26, the connection
patterns P1, P2, and P3 respectively correspond to connection
patterns illustrated in FIGS. 6 through 8.
[0107]
FIG. 27 is a graph showing a difference in magnitude of
25 electromagnetic forces F2 in the axial direction among
connection patterns in the three-phase coils 32 when the threephase coils 32 are energized in the magnetization process of
the magnetic material 22 according to the variation illustrated
in FIG. 16. In FIG. 27, the connection patterns P1, P2, and P3
30 respectively correspond to the connection patterns P1, P2, and
P3 in FIG. 26.
[0108]
As shown in FIGS. 26 and 27, in the magnetization process
of the magnetic material 22 according to the variation
38
illustrated in FIG. 16, the first connection state is also
preferably the connection pattern P1 or P2, and similarly, the
second connection state is preferably the connection pattern P1
or P2. Accordingly, in performing magnetization with the rotor
5 2 disposed inside the stator 3, significant deformation of the
three-phase coils 32, especially the external phase coil 323,
can be prevented. In addition, since deformation of the
external phase coil 323 is suppressed, performance of the
electric motor 1, such as electrical insulation of the external
10 phase coil 323, can be obtained.
[0109]
FIG. 28 is a graph showing a difference in magnitude of
electromagnetic forces F1 in the radial direction among
connection patterns in the three-phase coils 32 when the three15 phase coils 32 are energized in the magnetization process of
the magnetic material 22 according to the variation illustrated
in FIG. 16. Data shown in FIG. 28 is an analysis result of an
electromagnetic field analysis. In FIG. 28, the connection
patterns P4, P5, and P6 respectively correspond to connection
20 patterns illustrated in FIGS. 9 through 11.
[0110]
FIG. 29 is a graph showing a difference in magnitude of
electromagnetic forces F2 in the axial direction among
connection patterns in the three-phase coils 32 when the three25 phase coils 32 are energized in the magnetization process of
the magnetic material 22 according to the variation illustrated
in FIG. 16. In FIG. 29, the connection patterns P4, P5, and P6
respectively correspond to the connection patterns P4, P5, and
P6 in FIG. 28.
30 [0111]
As shown in FIGS. 28 and 29, in the magnetization process
of the magnetic material 22 according to the variation
illustrated in FIG. 16, the first connection state is also
preferably the connection pattern P4 or P5, and similarly, the
39
second connection state is preferably the connection pattern P4
or P5. Accordingly, in performing magnetization with the rotor
2 disposed inside the stator 3, significant deformation of the
three-phase coils 32, especially the external phase coil 323,
5 can be prevented. In addition, since deformation of the
external phase coil 323 is suppressed, performance of the
electric motor 1, such as electrical insulation of the external
phase coil 323, can be obtained.
[0112]
10 The variation illustrated in FIG. 16 also has
characteristics shown in FIGS. 22 and 25. Thus, in the
variation illustrated in FIG. 16, advantages shown in FIGS. 22
and 25 can be obtained.
[0113]
15 As described above, in this embodiment, in performing
magnetization with the rotor 2 disposed inside the stator 3,
significant deformation of the three-phase coils 32, especially
the external phase coil 323, can be prevented. In addition, in
this embodiment, the highly efficient electric motor 1 can be
20 provided.
[0114]
SECOND EMBODIMENT
A compressor 300 according to a second embodiment of the
present invention will be described.
25 FIG. 30 is a cross-sectional view schematically
illustrating a configuration of the compressor 300.
[0115]
The compressor 300 includes an electric motor 1 as an
electric element, a closed container 307 as a housing, and a
30 compression mechanism 305 as a compression element (also
referred to as a compression device). In this embodiment, the
compressor 300 is a scroll compressor. It should be noted that
the compressor 300 is not limited to the scroll compressor.
The compressor 300 may be a compressor other than the scroll
40
compressor, such as a rotary compressor.
[0116]
The electric motor 1 in the compressor 300 is the
electric motor 1 described in the first embodiment. The
5 electric motor 1 drives the compression mechanism 305.
[0117]
The compressor 300 also includes a subframe 308
supporting a lower end (i.e., an end opposite to the
compression mechanism 305) of a shaft 4.
10 [0118]
The compression mechanism 305 is disposed in the closed
container 307. The compression mechanism 305 includes a fixed
scroll 301 having a spiral part, an orbiting scroll 302 having
a spiral part forming a compression chamber with the spiral
15 part of the fixed scroll 301, a compliance frame 303 holding
the upper end of the shaft 4, and a guide frame 304 fixed to
the closed container 307 to hold the compliance frame 303.
[0119]
A suction pipe 310 penetrating the closed container 307
20 is press-fitted in the fixed scroll 301. The closed container
307 is provided with a discharge pipe 306 that discharges a
high-pressure refrigerant gas from the fixed scroll 301 to the
outside. The discharge pipe 306 communicates with an opening
provided between the compression mechanism 305 of the closed
25 container 307 and the electric motor 1.
[0120]
The electric motor 1 is fixed to the closed container 307
by fitting the stator 3 in the closed container 307. The
configuration of the electric motor 1 has been described above.
30 A glass terminal 309 for supplying electric power to the
electric motor 1 is fixed to the closed container 307 by
welding.
[0121]
When the electric motor 1 rotates, this rotation is
41
transferred to the orbiting scroll 302 to cause the orbiting
scroll 302 to orbit. When the orbiting scroll 302 orbits, the
volume of the compression chamber formed by the spiral part of
the orbiting scroll 302 and the spiral part of the fixed scroll
5 301 varies. Thereafter, a refrigerant gas is sucked from the
suction pipe 310, and is discharged from the discharge pipe 306.
[0122]
The compressor 300 includes the electric motor 1
described in the first embodiment, and thus, has advantages
10 described in the first embodiment.
[0123]
In addition, since the compressor 300 includes the
electric motor 1 described in the first embodiment, the highly
efficient compressor 300 can be provided.
15 [0124]
THIRD EMBODIMENT
A refrigeration air conditioning apparatus 7 as an air
conditioner including a compressor 300 according to a third
embodiment of the present invention will be described.
20 FIG. 31 is a diagram schematically illustrating a
configuration of the refrigeration air conditioning apparatus 7
according to the third embodiment.
[0125]
The refrigeration air conditioning apparatus 7 is capable
25 of performing cooling and heating operations, for example. A
refrigerant circuit diagram illustrated in FIG. 31 is an
example of a refrigerant circuit diagram of an air conditioner
capable of performing cooling and heating operations.
[0126]
30 The refrigeration air conditioning apparatus 7 according
to the third embodiment includes an outdoor unit 71, an indoor
unit 72, and refrigerant piping 73 connecting the outdoor unit
71 and the indoor unit 72 to each other.
[0127]
42
The outdoor unit 71 includes the compressor 300, a
condenser 74 as a heat exchanger, a throttling device 75, and
an outdoor fan 76 (first fan). The condenser 74 condenses a
refrigerant compressed by the compressor 300. The throttling
5 device 75 reduces the pressure of the refrigerant condensed by
the condenser 74 to adjust a flow rate of the refrigerant. The
throttling device 75 is also referred to as a pressure-reducing
device.
[0128]
10 The indoor unit 72 includes an evaporator 77 as a heat
exchanger, and an indoor fan 78 (second fan). The evaporator
77 evaporates the refrigerant subjected to the pressure
reduction by the throttling device 75 to cool indoor air.
[0129]
15 A basic operation of a cooling operation by the
refrigeration air conditioning apparatus 7 will be described
below. In the cooling operation, a refrigerant is compressed
by the compressor 300 and flows into the condenser 74. The
refrigerant is condensed by the condenser 74, and the condensed
20 refrigerant flows into the throttling device 75. The pressure
of the refrigerant is reduced by the throttling device 75, and
the refrigerant subjected to the pressure reduction flows into
the evaporator 77. In the evaporator 77, the refrigerant
evaporates, and the resulting refrigerant (specifically, a
25 refrigerant gas) flows into the compressor 300 of the outdoor
unit 71 again. When air is sent by the outdoor fan 76 to the
condenser 74, heat is exchanged between the refrigerant and air.
Similarly, when air is sent by the indoor fan 78 to the
evaporator 77, heat is exchanged between the refrigerant and
30 air.
[0130]
The configuration and operation of the refrigeration air
conditioning apparatus 7 described above are merely examples,
and are not limited to the examples described above.
43
[0131]
The refrigeration air conditioning apparatus 7 according
to the third embodiment has advantages described in the first
and second embodiments.
5 [0132]
In addition, since the refrigeration air conditioning
apparatus 7 according to the third embodiment includes the
compressor 300 according to the second embodiment, the highly
effective refrigeration air conditioning apparatus 7 can be
10 provided.
[0133]
Features of the embodiments and features of the variation
described above can be combined as appropriate.
15 DESCRIPTION OF REFERENCE CHARACTERS
[0134]
1 electric motor, 2 rotor, 3 stator, 7 refrigeration air
conditioning apparatus, 31 stator core, 32 three-phase coil,
32a coil end, 71 outdoor unit, 72 indoor unit, 211 magnet
20 insertion hole, 300 compressor, 305 compression mechanism, 307
closed container, 74 condenser, 77 evaporator, 321 internal
phase coil, 322 intermediate phase coil, 323 external phase
coil.

44
We Claim :
1. A method for producing an electric motor including a
stator and a rotor having a magnetic pole, the stator having a
5 stator core and three-phase coils attached to the stator core
by distributed winding, the rotor being disposed inside the
stator, the method comprising:
disposing the rotor inside the stator, the rotor having a
magnetic material that is not magnetized;
10 connecting a first phase coil of the three-phase coils to
a positive side of a source of electrical power for
magnetizing;
passing an electric current through the three-phase coils
in a state where a center of the magnetic pole of the rotor is
15 rotated a first angle with respect to a center of a magnetic
pole of the first phase coil in a first rotation direction of
the rotor, the magnetic pole of the first phase coil being
formed when the electric current flows through the first phase
coil from the source of electrical power;
20 switching a connection with the positive side of the
source of electrical power from the first phase coil to a
second phase coil of the three-phase coils; and
passing an electric current through the three-phase coils
in a state where the center of the magnetic pole of the rotor
25 is rotated a second angle with respect to a center of a
magnetic pole of the second phase coil in a second rotation
direction, the magnetic pole of the second phase coil being
formed when the electric current flows through the second phase
coil from the source of electrical power, the second rotation
30 direction being an opposite direction to the first rotation
direction of the rotor.
2. The method according to claim 1, wherein
the three-phase coils include the first phase coil, the
45
second phase coil, and a third phase coil,
in a coil end of the three-phase coils, the first phase
coil, the second phase coil, and the third phase coil are
arranged in this order in a circumferential direction of the
5 stator core, and
in the coil end, the second phase coil is located closer
to a center of the stator core than the third phase coil is.
3. The method according to claim 1, wherein
10 the three-phase coils include the first phase coil, the
second phase coil, and a third phase coil,
in a coil end of the three-phase coils, the second phase
coil, the first phase coil, and the third phase coil are
arranged in this order in a circumferential direction of the
15 stator core, and
in the coil end, the first phase coil is located closer
to a center of the stator core than the third phase coil is.
4. The method according to any one of claims 1 to 3, wherein
20 the three-phase coils include the first phase coil, the
second phase coil, and a third phase coil,
while the first phase coil is connected to the positive
side of the source of electrical power, an electric current
flowing from the source of electrical power to the first phase
25 coil is divided into an electric current flowing through the
second phase coil and an electric current flowing through the
third phase coil, and
while the second phase coil is connected to the positive
side of the source of electrical power, an electric current
30 flowing from the source of electrical power to the second phase
coil is divided into an electric current flowing through the
first phase coil and an electric current flowing into the third
phase coil.
46
5. The method according to claim 4, wherein
supposing θ1 is the first angle and θ2 is the second
angle,
the first angle θ1 satisfies 0 degrees < θ1 ≤ 10 degrees,
5 and
the second angle θ2 satisfies 0 degrees < θ2 ≤ 10 degrees.
6. The method according to any one of claims 1 to 3, wherein
the three-phase coils include the first phase coil, the
10 second phase coil, and a third phase coil,
while the first phase coil is connected to the positive
side of the source of electrical power, an electrical current
flowing from the source of electrical power to the first phase
coil flows through the second phase coil or the third phase
15 coil and does not flow through one of the second phase coil or
the third phase coil, and
while the second phase coil is connected to the positive
side of the source of electrical power, an electric current
flowing from the source of electrical power to the second phase
20 coil flows through the first phase coil or the third phase coil
and does not flow through one of the first phase coil or the
third phase coil.
7. The method according to claim 6, wherein
25 supposing θ1 is the first angle and θ2 is the second
angle,
the first angle θ1 satisfies 0 degrees < θ1 ≤ 12.5
degrees, and
the second angle θ2 satisfies 0 degrees < θ2 ≤ 12.5
30 degrees.
8. The method according to claim 1, wherein
the three-phase coils include the first phase coil, the
second phase coil, and a third phase coil,
47
the first phase coil comprises one or more first phase
coils, the number of the one or more first phase coils being
equal to the number of magnetic poles of the rotor,
the second phase coil comprises one or more second phase
5 coils, the number of the one or more second phase coils being
equal to the number of magnetic poles of the rotor, and
the third phase coil comprises one or more third phase
coils, the number of the one or more third phase coils is equal
to the number of magnetic poles of the rotor.
10
9. The method according to claim 8, wherein
the one or more first phase coils comprise a plurality of
first phase coils,
the one or more second phase coils comprise a plurality
15 of second phase coils,
the one or more third phase coils comprise a plurality of
third phase coils, and
in a coil end of the three-phase coils, coils of each
phase in the three-phase coils are concentrically arranged.
20
10. The method according to claim 8 or 9, wherein in a coil
end of the three-phase coils, the one or more first phase coils
are located outside the one or more second phase coils and the
one or more third phase coils are located outside the one or
25 more first phase coils, in a radial direction of the stator
core.
11. The method according to claim 8 or 9, wherein in a coil
end of the three-phase coils, the one or more second phase
30 coils are located outside the one or more first phase coils and
the one or more third phase coils are located outside the one
or more second phase coils, in a radial direction of the stator
core.
48
12. The method according to any one of claims 1 to 11,
wherein the three-phase coils are connected by Y-connection.
13. An electric motor comprising:
5 a stator having a stator core and three-phase coils, the
three-phase coils being attached to the stator core by
distributed winding; and
a rotor having a magnetic pole and disposed inside the
stator, wherein
10 the rotor includes
a stator core, and
a permanent magnet disposed in the stator core,
in a plane orthogonal to an axial direction of the rotor,
one end side of the permanent magnet is magnetized by passing
15 an electric current through the three-phase coils in a state
where a center of the magnetic pole of the rotor is rotated a
first angle with respect to a center of a magnetic pole of a
first phase coil of the three-phase coils in a first rotation
direction of the rotor, the magnetic pole of the first phase
20 coil being formed when the electric current flows through the
first phase coil from a source of electrical power for
magnetizing, and
in the plane orthogonal to the axial direction of the
rotor, another end side of the permanent magnet is magnetized
25 by passing an electric current through the three-phase coils in
a state where the center of the magnetic pole of the rotor is
rotated a second angle with respect to a center of a magnetic
pole of a second phase coil of the three-phase coils in a
second rotation direction of the rotor, the magnetic pole of
30 the second phase coil being formed when the electric current
flows through the second phase coil from the source of
electrical power, the second rotation direction being an
opposite direction to the first rotation direction of the rotor.
49
14. A compressor comprising:
a closed container;
a compression device disposed in the closed container;
and
5 the electric motor according to claim 13 to drive the
compression device.
15. An air conditioner comprising:
the compressor according to claim 14; and
10 a heat exchanger.