FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
STATOR, MOTOR, FAN, AIR CONDITIONER, AND MANUFACTURING METHOD OF
STATOR;
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
5
2
5 DESCRIPTION
TECHNICAL FIELD
[0001]
The present disclosure relates to a stator, a motor, a fan,
10 an air conditioner, and a manufacturing method of the stator.
BACKGROUND ART
[0002]
A stator of a motor includes a stator core which has an
annular core back and a plurality of teeth protruding inward in
15 the radial direction from the core back. The stator core is
covered with a mold resin part from outside. Recently, there is
a proposed stator including a stator having a core back divided
in the circumferential direction (see, for example, Patent
Reference 1).
20 PRIOR ART REFERENCE
PATENT REFERENCE
[0003]
Patent Reference 1: Japanese Patent Application
Publication No. 2007-325354 (see Abstract)
25 SUMMARY OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0004]
However, in a case where the core back is divided in the
circumferential direction, there tends to be variation in the
30 positions of the tip ends of the teeth. Consequently, an air
gap between the stator and the rotor tends to be non-uniform in
the circumferential direction, and vibration and noise are
likely to occur.
[0005]
35 The present disclosure is intended to solve the abovedescribed problem, and an object of the present disclosure is to
reduce vibration and noise.
3
5 MEANS OF SOLVING THE PROBLEM
[0006]
A stator according to the present disclosure includes a
stator core having a core back in an annular shape about an axis,
and a mold resin part surrounding the stator core from outside
10 in a radial direction about the axis. The mold resin part is
nonmagnetic. The stator core has a core-back gap passing in the
radial direction through at least a part of the core back in a
circumferential direction about the axis. The mold resin part
reaches an inner side of the core back in the radial direction
15 from an outer side of the core back in the radial direction
through the core-back gap.
EFFECTS OF THE INVENTION
[0007]
According to the present disclosure, the core-back gap is
20 provided to pass through the core back in the radial direction,
and thus molding can be performed in a state where tip ends of
teeth on the inner side in the radial direction are pressed
against a positioning surface of a mold. Thus, the misalignment
of the teeth in the radial direction is suppressed. In addition,
25 the mold resin part holds the core back from both the outer side
and the inner side in the radial direction, and thus it is
possible to suppress a reduction in the rigidity of the stator
core. As a result, vibration and noise can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
30 [0008]
FIG. 1 is a partial sectional view illustrating a motor of
a first embodiment.
FIG. 2 is a sectional view illustrating a rotor of the
first embodiment.
35 FIG. 3 is a plan view illustrating a stator core of the
first embodiment.
FIG. 4 is a plan view illustrating a stator of the first
embodiment.
4
5 FIG. 5(A) is a plan view illustrating a split core of the
first embodiment, and FIG. 5(B) is a plan view illustrating a
split core unit of the first embodiment.
FIG. 6 is a schematic diagram illustrating the split core
unit and a mold resin part of the first embodiment.
10 FIG. 7 is a diagram illustrating a mold stator of the
first embodiment as viewed from an opening side.
FIG. 8(A) is a perspective view illustrating the split
core of the first embodiment, and FIG. 8(B) is an enlarged
diagram illustrating a part of an insulator attached to the
15 split core of the first embodiment.
FIG. 9 is a schematic diagram illustrating tapered
portions of outer wall portions of the insulator of the first
embodiment.
FIG. 10 is a flowchart illustrating a manufacturing
20 process of the motor in the first embodiment.
FIG. 11 is a sectional view illustrating a mold in a
molding step of the stator in the first embodiment.
FIG. 12 is an enlarged schematic diagram illustrating a
part enclosed by a circle 12 in FIG. 11.
25 FIG. 13(A) is a sectional view illustrating the split core
unit and a center shaft of the mold of the first embodiment, and
FIG. 13(B) is an enlarged diagram illustrating a portion
enclosed by a circle 13B in FIG. 13(A).
FIG. 14 is a sectional view illustrating the mold in the
30 molding step of the stator in the first embodiment.
FIG. 15(A) is a diagram illustrating two split core units
of a stator of a second embodiment, and FIG. 15(B) is a diagram
illustrating a state where both split core units are connected.
FIG. 16 is a sectional view illustrating a split core unit
35 and a holding ring of a third embodiment, together with the
center shaft of the mold.
FIG. 17 is a sectional view illustrating a rotor of a
motor of a fourth embodiment.
5
5 FIG. 18(A) is a diagram illustrating an air conditioner to
which the motor of each embodiment is applicable, and FIG. 18(B)
is a sectional view illustrating an outdoor unit.
MODE FOR CARRYING OUT THE INVENTION
[0009]
10 Hereinafter, embodiments will be described in detail with
reference to the figures. The present disclosure is not limited
to these embodiments.
[0010]
First Embodiment
15 (Configuration of Motor 1)
FIG. 1 is a partial sectional view illustrating a motor 1
of a first embodiment. The motor 1 is used, for example, in a
fan of an air conditioner.
[0011]
20 The motor 1 includes a rotor 2 having a rotation shaft 11
and a mold stator 5. The rotation shaft 11 is a rotation shaft
of the rotor 2. The mold stator 5 has a stator 3 having an
annular shape and surrounding the rotor 2, a circuit board 6,
and a mold resin part 50 serving as a resin part covering these
25 components.
[0012]
In the description below, the direction of an axis C1,
which is a center axis of the rotation shaft 11, is referred to
as an “axial direction”. The circumferential direction
30 (indicated by an arrow R1 in FIGS. 2, 3 and other figures) about
the axis C1 of the rotation shaft 11 is referred to as a
"circumferential direction". The radial direction about the
axis C1 of the rotation shaft 11 is referred to as a "radial
direction".
35 [0013]
The rotation shaft 11 protrudes from the mold stator 5 to
the left side in FIG. 1. An impeller 505 (FIG. 18(A)) of a fan,
for example, is attached to an attachment portion 11a formed at
6
5 a protruding portion of the shaft. Thus, the protruding side
(the left side in FIG. 1) of the rotation shaft 11 is referred
to as a "load side", while the opposite side (the right side in
FIG. 1) thereof is referred to as a "counter-load side".
[0014]
10 (Configuration of Rotor 2)
FIG. 2 is a sectional view illustrating the rotor 2. As
illustrated in FIG. 2, the rotor 2 has the rotation shaft 11, a
rotor core 20 fixed to the rotation shaft 11, a plurality of
magnets 23 embedded in the rotor core 20, and a resin part 25
15 provided between the rotation shaft 11 and the rotor core 20.
[0015]
The rotor core 20 is a member having an annular shape
about the axis C1 and is provided on an outer side of the
rotation shaft 11 in the radial direction. The rotor core 20 is
20 composed of a plurality of electromagnetic steel sheets which
are stacked in the axial direction and fastened to each other in
the axial direction by crimping or the like. The sheet
thickness of each electromagnetic steel sheet is, for example,
0.1 mm to 0.7 mm.
25 [0016]
The rotor core 20 has a plurality of magnet insertion
holes 21. The magnet insertion holes 21 are arranged at equal
intervals in the circumferential direction and also at equal
distances from the axis C1. The number of magnet insertion
30 holes 21 is five in this example.
[0017]
The magnet insertion hole 21 extends linearly in a
direction orthogonal to a straight line in the radial direction
passing through a center of the magnet insertion hole 21 in the
35 circumferential direction. In this regard, the magnet insertion
hole 21 may also have a V shape such that its center in the
circumferential direction protrudes toward the axis C1.
7
5 [0018]
A flux barrier 22, which is a cavity, is formed at each
side of the magnet insertion hole 21 in the circumferential
direction. A thin-wall portion is formed between the flux
barrier 22 and an outer circumference of the rotor core 20. In
10 order to suppress the leakage flux between adjacent magnetic
poles, the thickness of the thin-wall portion is set equal to
the thickness of each electromagnetic steel sheet, for example.
[0019]
The magnet 23 is inserted in each magnet insertion hole 21.
15 The magnet 23 is composed of, for example, a rare earth magnet
that contains neodymium (Nd), iron (Fe) and boron (B), or a rare
earth magnet that contains samarium (Sm), iron and nitrogen (N).
The magnet 23 is in the form of a flat plate and has a
rectangular cross sectional shape in a plane orthogonal to the
20 axial direction. The magnet 23 is also referred to as a main
magnet.
[0020]
Five magnets 23 have the same magnetic poles on their
outer side in the radial direction. In the rotor core 20,
25 magnetic poles opposite to the magnets 23 are formed in regions
each between the magnets 23 adjacent in the circumferential
direction.
[0021]
Therefore, in the rotor 2, five first magnetic poles P1
30 formed by the magnets 23 and five second magnetic poles P2
formed by the rotor core 20 are arranged alternately in the
circumferential direction. The first magnetic pole P1 is also
referred to as a magnet magnetic pole, while the second magnetic
pole P2 is also referred to as a virtual magnetic pole. Such a
35 rotor 2 is referred to as a consequent-pole rotor.
[0022]
Hereinafter, when the term "magnetic pole" is simply used,
it refers to either the first magnetic pole P1 or the second
8
5 magnetic pole P2. The number of poles of the rotor 2 is ten.
The magnetic poles P1 and P2 of the rotor 2 are arranged at
equal angular intervals in the circumferential direction. A
boundary between the first magnet pole P1 and the second
magnetic pole P2 is defined as a pole boundary M.
10 [0023]
The outer circumference of the rotor core 20 has a socalled flower circle shape in a plane orthogonal to the axial
direction. In other words, the outer circumference of the rotor
core 20 has its maximum outer diameter at the pole center of
15 each of the magnetic poles P1 and P2 and minimum outer diameter
at each pole boundary M, and extends in an arc shape from the
pole center to the pole boundary M. The outer circumference of
the rotor core 20 is not limited to the flower circle shape and
may have a circular shape.
20 [0024]
The number of poles of the rotor 2 is ten in this example,
but it is sufficient that the number of poles is an even number
of four or more. Moreover, although one magnet 23 is disposed
in each magnet insertion hole 21 in this example, two or more
25 magnets 23 may be disposed in each magnet insertion hole 21.
[0025]
The nonmagnetic resin part 25 is provided between the
rotation shaft 11 and the rotor core 20. The resin part 25
holds the rotation shaft 11 and the rotor core 20 in a state
30 where the rotation shaft 11 and the rotor core 20 are separated
from each other. The resin part 25 is desirably composed of a
thermoplastic resin such as polybutylene terephthalate (PBT).
[0026]
The resin part 25 includes an annular inner cylindrical
35 portion 26 fixed to the rotation shaft 11, an annular outer
cylindrical portion 28 fixed to an inner circumference of the
rotor core 20, and a plurality of protrusions 27 connecting the
inner cylindrical portion 26 and the outer cylindrical portion
9
5 28. The protrusions 27 are arranged at equal intervals in the
circumferential direction about the axis C1. The number of the
protrusions 27 is, for example, half the number of poles, and is
five in this example.
[0027]
10 The rotation shaft 11 is fixed to the inside of the inner
cylindrical portion 26 of the resin part 25. The protrusions 27
are arranged at equal intervals in the circumferential direction
and radially extend outward in the radial direction from the
inner cylindrical portion 26. Hollow portions 29 are formed
15 each between the protrusions 27 that are adjacent in the
circumferential direction. In this example, the number of the
protrusions 27 is half the number of poles, and the positions of
the protrusions 27 in the circumferential direction coincide
with the pole centers of the second magnetic poles P2, but the
20 number and arrangement of the protrusions 27 are not limited
thereto.
[0028]
As illustrated in FIG. 1, a sensor magnet 24 is disposed
to face the rotor core 20 in the axial direction. The sensor
25 magnet 24 is held by the resin part 25. The sensor magnet 24
has magnetic poles, the number of which is the same as the
number of poles of the rotor 2. The magnetic field of the
sensor magnet 24 is detected by a magnetic sensor mounted on the
circuit board 6, by which the position of the rotor 2 in the
30 circumferential direction, i.e., the rotational position of the
rotor 2 is detected.
[0029]
The rotor 2 is not limited to the configuration in which
the rotor core 20 and the rotation shaft 11 are connected
35 together by the resin part 25 as described above. For example,
the rotation shaft 11 may be fitted to the inner circumference
of the rotor core 20.
10
5 [0030]
(Configuration of Mold Stator 5)
The mold stator 5 has the stator 3 and the mold resin part
50 as described above. The stator 3 surrounds the rotor 2 from
outside in the radial direction. The stator 3 has a stator core
10 30, insulators 40 as resin components provided on the stator
core 30, and coils 45 wound on the stator core 30 via the
insulators 40.
[0031]
The mold resin part 50 is desirably composed of a
15 thermosetting resin such as a bulk molding compound (BMC).
However, the mold resin part 50 may be composed of a
thermoplastic resin such as PBT or polyphenylene sulfide (PPS).
[0032]
The mold resin part 50 has a bearing holding portion 56 on
20 the counter-load side and an opening 57 on the load side. A
rotor housing portion 59, which is a space where the rotor 2 is
housed, is formed between the bearing holding portion 56 and the
opening 57. The rotor 2 is inserted into the rotor housing
portion 59 through the opening 57.
25 [0033]
One bearing 13 that supports the rotation shaft 11 is
supported by the bearing holding portion 56 of the mold resin
part 50. A metal bracket 15 is attached to a peripheral edge
57a surrounding the opening 57. The other bearing 12 that
30 supports the rotation shaft 11 is held by the bracket 15. A cap
14 for preventing the entry of water or the like is attached to
the outside of the bracket 15.
[0034]
FIG. 3 is a plan view illustrating the stator core 30.
35 The stator core 30 is composed of a plurality of electromagnetic
steel sheets which are stacked in the axial direction and
fastened to each other in the axial direction by crimping or the
like. The sheet thickness of each electromagnetic steel sheet
11
5 is, for example, 0.1 mm to 0.7 mm.
[0035]
The stator core 30 has a core back 31 having an annular
shape about the axis C1 and a plurality of teeth 32 extending
inward in the radial direction from the core back 31. The teeth
10 32 are arranged at equal intervals in the circumferential
direction. A tip end 32a of each tooth 32 on an inner side in
the radial direction faces an outer circumference of the rotor 2
(FIG. 1). The number of the teeth 32 is 12 in this example, but
is not limited to 12.
15 [0036]
Slots 34 for housing the coils 45 are formed each between
adjacent two teeth 32. A slot opening S is formed on the inner
side of each slot 34 in the radial direction. The slot opening
S is formed between the tip ends 32a of the adjacent teeth 32.
20 [0037]
The stator core 30 is divided into a plurality of split
cores 33 each including one tooth 32. An arc-shaped portion of
the annular core back 31 that is included in each split core 33
is referred to as a core-back part 31A. The number of split
25 cores 33 is 12 in this example, but it is sufficient that the
number of split cores 33 is the same as the number of teeth 32.
[0038]
Split cores 33 that are adjacent in the circumferential
direction are not connected to each other. That is, a gap is
30 formed between ends 313 of adjacent core-back parts 31A in the
circumferential direction. The gap is referred to as a coreback gap G. The core-back gaps G are gaps by which the annular
core back 31 are divided into the plurality of core-back parts
31A.
35 [0039]
FIG. 4 is a diagram illustrating a state in which the
insulators 40 are attached to the split cores 33 of the stator
core 30, and the coils 45 are wound around the insulators 40.
12
5 In FIG. 4, three of the twelve teeth 32 of the stator 3 are
indicated by dashed lines.
[0040]
Each insulator 40 has a body portion 43 as a coil winding
portion formed to surround the tooth 32, a wall portion 41
10 located on the outer side of the body portion 43 in the radial
direction, and a flange portion 42 located on the inner side of
the body portion 43 in the radial direction. The wall portion
41, the flange portion 42, and the body portion 43 are formed
integrally.
15 [0041]
The wall portion 41 and the flange portion 42 face each
other in the radial direction. The wall portion 41 and the
flange portion 42 guide the coil 45 wound around the body
portion 43, from both sides of the coil 45 in the radial
20 direction.
[0042]
The coil 45 is, for example, a magnet wire, and is wound
around the tooth 32 via the insulator 40. A portion of the coil
45 that is wound around each tooth 32 is also referred to as a
25 winding portion.
[0043]
The insulator 40 is composed of a thermoplastic resin such
as PBT, for example. The insulator 40 is formed by, for example,
assembling a molded body of a thermoplastic resin to the stator
30 core 30, but may be formed by molding a thermoplastic resin
integrally with the stator core 30.
[0044]
With reference to FIG. 1 again, the circuit board 6 is
disposed on the counter-load side of the stator 3. The circuit
35 board 6 is a printed board on which a driving circuit 61, such
as a power transistor for driving the motor 1, is mounted. Lead
wires 63 are wired on the circuit board 6. The lead wires 63 on
the circuit board 6 are drawn to the outside of the motor 1
13
5 through a lead wire outlet part 62 attached to an outer
circumferential portion of the mold resin part 50.
[0045]
A heat dissipation member 7 is attached to the mold resin
part 50. The heat dissipation member 7 dissipates heat
10 generated in the stator 3 and the circuit board 6, to the
outside. A description of the heat dissipation member 7 is
omitted.
[0046]
FIG. 5(A) is a plan view illustrating the split core 33.
15 As illustrated in FIG. 5(A), the core-back part 31A of the split
core 33 has an outer circumference 311 on the outer side in the
radial direction, an inner circumferential surface 312 on the
inner side in the radial direction, and the ends 313 on both
sides in the circumferential direction.
20 [0047]
The split core 33 is composed of a stacked body of a
plurality of electromagnetic steel sheets which are stacked in
the axial direction and fastened together by crimping portions
33a. The crimping portions 33a are formed, for example, in the
25 core-back part 31A and the tooth 32, but they are not limited to
such positions. In the figures other than FIG. 5(A), the
crimping portions 33a are omitted.
[0048]
FIG. 5(B) is a plan view illustrating a state in which the
30 insulator 40 and the coil 45 are attached to the split core 33.
The split core 33, the insulator 40, and the coil 45 constitute
a split core unit 35.
[0049]
Each split core unit 35 can be handled independently.
35 Twelve split core units 35 are placed in a mold 200 (FIG. 11)
and integrally molded using a mold resin together with the
circuit board 6, so that the mold stator 5 illustrated in FIG. 1
is obtained.
14
5 [0050]
FIG. 6 is an enlarged diagram illustrating two adjacent
split core units 35. As described above, the core-back gap G is
formed between the ends 313 of the adjacent two core-back parts
31A. The slot opening S is formed between the tip ends 32a of
10 the adjacent two teeth 32.
[0051]
The mold resin part 50 reaches an inner side of the core
back 31 in the radial direction from an outer side of the core
back 31 in the radial direction through the core-back gap G.
15 [0052]
More specifically, the mold resin part 50 has an outer
circumferential resin portion 51 covering the outer
circumference 311 of the core-back part 31A, a gap resin portion
52 located in the core-back gap G, and an in-slot resin portion
20 53 located between adjacent winding portions of the coils 45.
[0053]
The in-slot resin portion 53 of the mold resin part 50
reaches the slot opening S. A recess 55 is formed at the end of
the in-slot resin portion 53 on the inner side in the radial
25 direction. The recess 55 is formed by rib 212 (FIG. 13(B)) of
the mold 200 during molding as described below.
[0054]
A surface resin layer 54 is formed on a surface of the tip
end 32a of the tooth 32, i.e., an end surface of the tooth 32 on
30 the inner side in the radial direction. The surface resin layer
54 is formed because a part of the mold resin flows onto the
surface of the tip end 32a of the tooth 32 during molding.
[0055]
FIG. 7 is a diagram illustrating the mold stator 5 as
35 viewed from the opening 57 side. When the mold stator 5 is
viewed from the opening 57 side, the surface resin layers 54 are
seen around the rotor housing portion 59 inside the mold resin
part 50. Further, the recesses 55 are seen adjacent to the
15
5 surface resin layers 54.
[0056]
Attachment legs 58 are formed at the outer circumference
of the mold resin part 50. In this example, four attachment
legs 58 are formed at intervals of 90 degrees about the axis C1.
10 In this regard, the number of attachment legs 58 is not limited
to four. It is sufficient that the number of attachment legs 58
is one or more. Each attachment leg 58 is provided with a hole
through which a screw for fixing the motor 1 to a frame of an
air conditioner or the like is inserted.
15 [0057]
FIG. 8(A) is a perspective view illustrating the split
core unit 35. The wall portion 41 of the insulator 40 is
provided at each end of the core-back part 31A in the axial
direction. The wall portion 41 provided at one end of the core20 back part 31A in the axial direction is referred to as a wall
portion 41a, while the wall portion 41 provided at the other end
thereof is referred to as a wall portion 41b.
[0058]
The side on which the wall portion 41a is provided in the
25 axial direction is a side where the circuit board 6 (FIG. 1) is
attached. A terminal 41c connected to the coil 45, or a pin
inserted into an attachment hole of the circuit board 6 is
disposed at the wall portion 41a of the insulator 40.
[0059]
30 The flange portion 42 of the insulator 40 has a flange
portion 42a protruding from the tip end 32a of the tooth 32
toward one side in the axial direction and a flange portion 42b
protruding from the tip end 32a toward the other side in the
axial direction. In the axial direction, the flange portion 42a
35 is located on the same side as the wall portion 41a, while the
flange portion 42b is located on the same side as the wall
portion 41b.
[0060]
16
5 FIG. 8(B) is a diagram illustrating the flange portion 42b
as viewed from its inner side in the radial direction, i.e., the
rotor 2 (FIG. 1) side. The flange portion 42b has a protrusion
42c at an end surface 420 in the axial direction (at the lower
surface in FIG. 8(B)).
10 [0061]
The protrusion 42c has support surfaces 421 on both sides
thereof in the circumferential direction. Each support surface
421 is inclined with respect to the circumferential direction
and the axial direction. More specifically, the support surface
15 421 is inclined so as to be displaced inward of the protrusion
42c in the circumferential direction as the distance from the
end surface 420 in the axial direction increases.
[0062]
The protrusion 42c of the flange portion 42 is engaged
20 with a positioning recess 206 of the mold 200 (FIG. 11) during
molding. The positioning recess 206 has contact surfaces 207
corresponding to the support surfaces 421 of the protrusion 42c.
[0063]
By contact between the support surfaces 421 of the
25 protrusion 42c and the contact surfaces 207 of the positioning
recess 206, the split core unit 35 can be positioned in the
circumferential direction when the split core units 35 are
placed in the mold 200.
[0064]
30 FIG. 9 is a schematic diagram for explaining the shapes of
the wall portions 41a and 41b of the insulator 40. Each of the
wall portions 41a and 41b has a tapered surface 412 as a contact
surface at its end in the axial direction.
[0065]
35 The tapered surfaces 412 are formed from the ends in the
axial direction of the wall portions 41a and 41b to outer wall
surfaces 411 in the radial direction of the wall portions 41.
Each tapered surface 412 is inclined with respect to the radial
17
5 direction and the axial direction. More specifically, the
tapered surface 412 is inclined so as to be displaced inward in
the radial direction as the distance from the core-back part 31A
in the axial direction increases.
[0066]
10 The tapered surfaces 412 of the wall portions 41a and 41b
are brought into contact with contact positioning pins 208 and
209 of the mold 200 during molding. Each of the positioning
pins 208 and 209 has an inclined surface corresponding to the
tapered surface 412.
15 [0067]
The tapered surfaces 412 of the insulator 40 are brought
into contact with the positioning pins 208 and 209 of the mold
200, so that the split core unit 35 is pressed inward in the
radial direction. Thus, the tip end 32a of the tooth 32 is
20 pressed against a center shaft 205 (FIG. 11) of the mold 200,
and thus the positioning accuracy of the tooth 32 in the radial
direction can be improved.
[0068]
In this regard, it is sufficient that the tapered surface
25 412 is formed in at least a portion in the circumferential
direction of at least one of the ends of the wall portion 41a
and 41b in the axial direction. In FIG. 9, the positioning pins
208 and 209 of the mold 200 is schematically illustrated. The
specific shapes of the positioning pins 208 and 209 are
30 illustrated in FIG. 11 to be described later.
[0069]
(Manufacturing Method of Motor 1)
Next, a manufacturing method of the motor 1 will be
described. FIG. 10 is a flowchart illustrating a manufacturing
35 process of the motor 1.
[0070]
In the manufacturing process of the motor 1, first, a
plurality of stacking elements are stacked in the axial
18
5 direction and integrally fixed together by crimping or the like,
thereby forming the split cores 33 (step S101).
[0071]
Then, a preliminarily molded insulator 40 is attached to
each split core 33 (step S102). Further, the coil 45 is wound
10 on the split core 33 via the insulator 40 (step S103). In this
way, the split core unit 35 is formed.
[0072]
Twelve split core units 35 formed as above are placed in
the mold 200 for molding. This step corresponds to a step of
15 placing the stator core 30 in the mold 200.
[0073]
FIG. 11 is a sectional view illustrating the mold 200 used
in the molding step. As illustrated in FIG. 11, the mold 200
includes an upper mold 201 and a lower mold 202. A cavity 204
20 is formed between both molds 202 and 204.
[0074]
The upper mold 201 is movable in the direction toward and
away from the lower mold 202, here in the vertical direction.
In the state illustrated in FIG. 11, the upper mold 201 is in a
25 position (upper position) apart from the lower mold 202 to make
the cavity 204 open.
[0075]
The lower mold 202 has a center shaft 205 as the center
core in the cavity 204. The center shaft 205 protrudes in the
30 axial direction from the bottom of the cavity 204. The center
shaft 205 has a bearing-shaped portion 205a corresponding to the
bearing 13 (FIG. 1), a core-shaped portion 205b corresponding to
the rotor core 20 (FIG. 1), a step portion 205c corresponding to
the opening 57 (FIG. 1), and a large-diameter portion 205d
35 corresponding to the peripheral edge 57a (FIG. 1) around the
opening 57.
[0076]
The lower mold 202 is provided with a runner 210, which is
19
5 a flow path for molten resin injected into the cavity 204, and a
gate 211, which is an inlet for molten resin injected from the
runner 210 into the cavity 204.
[0077]
The twelve split core units 35 are placed in the cavity
10 204 of the lower mold 202. These twelve split core units 35 are
arranged around the center shaft 205 of the mold 200 as
illustrated in FIG. 11.
[0078]
FIG. 12 is an enlarged diagram illustrating a part
15 enclosed by a circle 12 in FIG. 11. The positioning recess 206
is formed in the step portion 205c of the lower mold 202. The
positioning recess 206 is engaged with the protrusion 42c of the
flange portion 42b as described with reference to FIG. 8(B).
[0079]
20 By the engagement between the positioning recesses 206 and
the protrusions 42c of the flange portions 42b, the split core
units 35 placed in the cavity 204 are positioned in the
circumferential direction. The positioning recesses 206, the
number of which is the same as the number of split core units 35,
25 are desirably provided at equal intervals in the circumferential
direction.
[0080]
FIG. 13 is a diagram illustrating a state in which the
split core units 35 are arranged around the center shaft 205 as
30 viewed from the upper mold 201 side. The tip ends 32a of the
teeth 32 of the split core units 35 are brought into contact
with an outer circumferential surface of the center shaft 205,
i.e., the positioning surface. Thus, the tip ends 32a of the
teeth 32 can be positioned in the radial direction with high
35 accuracy.
[0081]
Ribs 212 (FIG. 13(B)) are formed on the outer
circumference of the center shaft 205 is provided with the ribs
20
5 212. Each rib 212 is engaged between the tip ends 32a of the
adjacent teeth 32. The ribs 212, the number of which is the
same as the number of split core units 35, are desirably
provided at equal intervals in the circumferential direction.
With these ribs 212, the split core units 35 can be positioned
10 in the circumferential direction.
[0082]
Each rib 212 may be formed in a rail shape elongated in
the axial direction. Alternatively, each rib 212 may be formed
of a plurality of protrusions that are formed at intervals in
15 the axial direction.
[0083]
The circuit board 6 is placed on the split core units 35
disposed in the cavity 204 as above (step S105).
[0084]
20 Then, the upper mold 201 of the mold 200 is moved downward
to close the cavity 204 as illustrated in FIG. 14, and integral
molding is performed with a mold resin (step S106).
[0085]
The upper mold 201 and the lower mold 202 are provided
25 with the positioning pins 208 and 209 as the positioning
portions that protrude inside the cavity 204. The positioning
pins 208 and 209 are brought into contact with the tapered
surfaces 412 (FIG. 9) of the wall portions 41a and 41b of the
insulators 40 so as to press the split core units 35 inward in
30 the radial direction.
[0086]
Thus, the tip ends 32a of the teeth 32 can be brought into
contact with the center shaft 205 more surely. The positioning
pins 208, the number of which is the same as the number of split
35 core units 35, are desirably provided at equal intervals in the
circumferential direction. The positioning pins 209, the number
of which is the same as the number of split core units 35, are
desirably provided at equal intervals in the circumferential
21
5 direction.
[0087]
Then, a mold resin in a molten state is injected into the
cavity 204 through the runner 210 and the gate 211. The mold
resin injected into the cavity 204 covers the split core units
10 35 and the circuit board 6 and further covers the outer
circumference side of the bearing holding portion 56. This step
S106 corresponds to a step of molding the stator core 30
integrally with the mold resin.
[0088]
15 In a case where a thermosetting resin such as BMC is used
as the mold resin, the mold resin is injected into the cavity
204, and then the mold 200 is heated so as to harden the mold
resin in the cavity 204. In this way, the mold resin part 50 is
formed. That is, the mold stator 5 in which the split core
20 units 35 and the circuit board 6 are covered with the mold resin
part 50 is formed.
[0089]
Aside from steps S101 to S106, the rotor 2 is assembled.
That is, a plurality of stacking elements are stacked in the
25 axial direction and integrally fixed together by crimping or the
like, thereby forming the rotor core 20. Then, the magnets 23
are inserted in the magnet insertion holes 21. Furthermore, the
rotation shaft 11, the rotor core 20, the magnets 23, and the
sensor magnet 24 are formed integrally with a resin which is to
30 be the resin part 25. Thereafter, the bearings 12 and 13 are
attached to the rotation shaft 11, and the rotor 2 is completed.
[0090]
Then, the rotor 2 is inserted into the rotor housing
portion 59 through the opening 57 of the mold stator 5, and the
35 bracket 15 is fitted to the peripheral edge 57a of the opening
57 (step S107). Thus, the bearing 13 is attached to the bearing
holding portion 56, while the bearing 12 is attached to the
bracket 15. Further, the cap 14 is attached to the outside of
22
5 the bracket 15. Consequently, the motor 1 is completed.
[0091]
Of steps S101 to S107 described above, steps S101 to S106
correspond to the manufacturing process of the stator 3 and also
correspond to the manufacturing process of the mold stator 5.
10 [0092]
(Function)
Conventionally, there is a stator core in which a
plurality of split cores are connected together by thin-wall
portions, for the purpose of facilitating winding of coils.
15 With this configuration, the mutual positional relationship
between the split cores is determined by the thin-wall portions,
and thus the tip ends of all the teeth cannot be pressed against
the positioning surface of the mold. Accordingly, there tends
to be variation in the positions of the tip ends of the teeth in
20 the radial direction. Therefore, the air gap between the stator
and the rotor may be non-uniform in the circumferential
direction.
[0093]
In contrast, in the motor 1 of the first embodiment, the
25 plurality of split cores 33 constituting the stator core 30 are
not connected by thin-wall portions, but are separated from each
other via the core-back gaps G. Thus, the tip ends 32a of all
the teeth 32 can be brought into contact with the outer
circumferential surface of the center shaft 205 when the
30 plurality of split core units 35 are placed in the mold 200.
[0094]
Thus, the tip ends 32a of all the teeth 32 can be
positioned in the radial direction with high accuracy.
Accordingly, the air gap between the stator 3 and the rotor 2
35 can be made uniform in the circumferential direction, and
vibration and noise can be reduced.
[0095]
The mold resin part 50 reaches the inner side of the core
23
5 back 31 in the radial direction from the outer side of the core
back 31 in the radial direction through the core-back gaps G,
and thus it is possible to suppress a reduction in the rigidity
due to the division of the core back 31 through the core-back
gaps G.
10 [0096]
In particular, in the motor 1 having the consequent-pole
rotor 2, the first magnetic pole P1, which is the magnet
magnetic pole, and the second magnetic pole P2, which is the
virtual magnetic pole, differ in the inductance, and thus
15 vibration and noise tend to increase. However, in the first
embodiment, the air gap between the stator 3 and the rotor 2 can
be made uniform in the circumferential direction, and thus a
large effect is obtained in reducing vibration and noise in the
motor 1 having the consequent-pole rotor 2.
20 [0097]
The mold resin part 50 has the recesses 55 in the slot
opening S. The recesses 55 are formed because the ribs 212 of
the center shaft 205 of the mold 200 are engaged between the tip
ends 32a of the adjacent teeth 32 of the stator core 30 during
25 molding. With these ribs 212, the teeth 32 can be positioned in
the circumferential direction.
[0098]
The insulator 40 has the protrusion 42c, and the
protrusion 42c has the support surfaces 421. The support
30 surfaces 421 of the protrusion 42c is brought into contact with
the contact surfaces 207 of the positioning recess 206 of the
mold 200, and thus each split core unit 35 can be positioned in
the circumferential direction. Thus, the positioning accuracy
of each tooth 32 in the circumferential direction can be
35 improved.
[0099]
The protrusion 42c of the insulator 40 is engaged with the
positioning recess 206 of the mold 200 during molding and thus
24
5 is not covered with the mold resin. Thus, after the molding,
the protrusion 42c is exposed to the outside from the mold resin
part 50. For this reason, the protrusion 42c of the insulator
40 is also referred to an exposed portion.
[0100]
10 Although the protrusion 42c is provided on the flange
portion 42 of the insulator 40 in this example, the protrusion
42c may be provided on any other portions of the insulator 40.
Further, the protrusion 42c is not necessarily provided on the
insulator 40, but may be provided on any resin component
15 attached to the split core 33.
[0101]
The tapered surfaces 412 as the contact surfaces are
formed at the ends of the wall portions 41a and 41b of the
insulator 40 in the axial direction. The tapered surfaces 412
20 are brought into contact with the positioning pins 208 and 209
of the mold 200, thereby pressing the split core units 35 toward
the center shaft 205. Thus, each tooth 32 can be more surely
pressed against the center shaft 205, and thus the positioning
accuracy of each tooth 32 in the radial direction can be
25 improved.
[0102]
The tapered surfaces 412 of the insulator 40 are brought
into contact with the positioning pins 208 and 209 of the mold
200 during molding and thus are not covered with the mold resin.
30 Thus, after the molding, each tapered surfaces 412 is exposed to
the outside from the mold resin part 50. For this reason, the
tapered surface 412 is also referred to the exposed portion.
[0103]
Although the tapered surface 412 is provided in each of
35 the wall portions 41a and 41b of the insulator 40 in this
example, the tapered surface 412 may be provided in any other
portions of the insulator 40. Further, the tapered surface 412
is not necessarily provided on the insulator 40, but may be
25
5 provided on any resin component attached to the split core 33.
[0104]
A gate mark is left on the outer circumferential portion
of the mold resin part 50, and the gate mark has a shape
corresponding to the gate 211 of the mold 200. Since the mold
10 resin flows from the gate 211 of the mold 200 toward each split
core units 35, the split core units 35 are pressed toward the
center shaft 205 side due to the pressure of the mold resin.
Thus, the positioning accuracy of each tooth 32 in the radial
direction can be further improved.
15 [0105]
The volume of a portion of the mold resin part 50 that is
located on the outer side in the radial direction with respect
to the stator core 30 is represented by V1, while the volume of
a portion of the mold resin part 50 that is located on the inner
20 side in the radial direction with respect to the stator core 30
is represented by V2. More specifically, the volume V1 is a
volume of the outer circumferential resin portion 51 illustrated
in FIG. 6, while the volume V2 is a volume of the surface resin
layer 54 illustrated in FIG. 6. The volumes V1 and V2 do not
25 include a portion protruding from the stator core 30 in the
axial direction (for example, the bearing holding portion 56).
[0106]
In this example, as can be seen from FIG. 6, the volumes
V1 and V2 satisfy V1 > V2. That is, within the mold 200, the
30 amount of mold resin located on the outer side in the radial
direction with respect to the split core 33 is larger than the
amount of mold resin located on the inner side in the radial
direction with respect to the split core 33. Thus, the split
cores 33 are pressed toward the center shaft 205 side by the
35 pressure of the mold resin, so that the positioning accuracy of
each tooth 32 in the radial direction is further improved.
[0107]
In this example, the annular core back 31 is divided into
26
5 the plurality of core-back parts 31A via the core-back gaps G.
However, the first embodiment is not limited to such a
configuration. It is sufficient that the core-back gap G is
formed so as to pass in the radial direction through at least a
part of the core back 31 in the circumferential direction.
10 [0108]
(Effects of Embodiment)
As described above, the stator 3 of the first embodiment
has the stator core 30 having the core back 31 and the teeth 32,
and the mold resin part 50 surrounding the stator core 30 from
15 outside in the radial direction. The stator core 30 has the
core-back gap G which passes in the radial direction through at
least a part of the core back 31 in the circumferential
direction. The mold resin part 50 reaches the inner side of the
core back 31 in the radial direction from the outer side of the
20 core back 31 in the radial direction through the core-back gap G.
[0109]
Since the core-back gap G is formed to pass in the radial
direction through at least a part of the core back 31 in the
circumferential direction as above, the molding can be performed
25 by pressing the tip ends 32a of the teeth 32 against the outer
circumferential surface (the positioning surface) of the center
shaft 205 of the mold 200. Thus, the tip ends 32a of the teeth
32 can be positioned in the radial direction with high accuracy,
and therefore the air gap between the stator 3 and the rotor 2
30 can be made uniform in the circumferential direction. Since the
mold resin part 50 holds the core back 31 from both the outer
side and the inner side in the radial direction, a reduction in
the rigidity of the stator core 30 can be suppressed. As a
result, vibration and noise of the motor 1 can be reduced.
35 [0110]
The mold resin part 50 has the recess 55 in the slot
opening S. The recess 55 is formed because the rib 212 of the
mold 200 is engaged between the tip ends 32a of the adjacent
27
5 teeth 32. Since the rib 212 of the mold 200 is engaged between
the tip ends 32a of the adjacent teeth 32, each tooth 32 can be
positioned in the circumferential direction.
[0111]
Since the insulator 40 as the resin component has the
10 protrusion 42c having the support surfaces 421 in the
circumferential direction, each split core unit 35 can be
positioned in the circumferential direction by the contact
between the support surfaces 421 and the contact surfaces 207 of
the mold 200. Thus, the positioning accuracy of each tooth 32
15 in the circumferential direction can be improved.
[0112]
In addition, since the wall portions 41a and 41b have the
tapered surfaces 412 as the contact surfaces at their ends in
the axial direction, each split core unit 35 can be positioned
20 in the radial direction, and thus each tooth 32 can be
positioned in the radial direction.
[0113]
A gate mark is formed on the outer circumference of the
mold resin part 50. This is because the gate 211 is disposed in
25 the position facing the outer circumference of the split core 33
in the cavity 204 of the mold 200. Thus, each split core unit
35 can be pressed toward the center shaft 205 side by the
pressure of the mold resin flowing through the gate 211, and the
positioning accuracy of each tooth 32 in the radial direction
30 can be improved.
[0114]
In the mold resin part 50, the volume V1 of the portion
located on the outer side in the radial direction with respect
to the stator core 30 and the volume V2 of the portion located
35 on the inner side in the radial direction with respect to the
stator core 30 satisfy V1 > V2. Thus, the amount of mold resin
located on the outer side in the radial direction with respect
to each split core 33 is larger than the amount of mold resin
28
5 located on the inner side in the radial direction with respect
to each split core 33 within the mold 200. Therefore, each
split core 33 can be pressed toward the center shaft 205 side by
the pressure of the mold resin, and thus the positioning
accuracy of each tooth 32 in the radial direction can be further
10 improved.
[0115]
In the motor 1 having the consequent-pole rotor 2,
vibration and noise tend to be large. Thus, by making the air
gap between the stator 3 and the rotor 2 uniform in the
15 circumferential direction, a large effect is obtained in
reducing vibration and noise.
[0116]
Second Embodiment
Next, a second embodiment will be described. FIG. 15(A)
20 is a diagram illustrating two split core units 35 that are
adjacent in the circumferential direction in a stator 3 of the
second embodiment.
[0117]
As described in the first embodiment, the split core unit
25 35 has the split core 33, the insulator 40, and the coil 45.
The insulator 40 has the wall portion 41, the flange portion 42,
and the body portion 43 (FIG. 4).
[0118]
In the second embodiment, a convex portion 401 and a
30 concave portion 402 are provided on the flange portion 42 of the
insulator 40 of each split core unit 35.
[0119]
The convex portion 401 protrudes in the circumferential
direction from one end of the flange portion 42 in the
35 circumferential direction. The concave portion 402 is opened at
the other end of the flange portion 42 in the circumferential
direction. Each of the convex portion 401 and the concave
portion 402 has, for example, a circular shape in a plane
29
5 orthogonal to the axial direction.
[0120]
When two split core units 35 are assembled as indicated by
the arrow, the convex portion 401 of one split core unit 35 is
engaged with the concave portion 402 of its adjacent split core
10 unit 35 as illustrated in FIG. 15(B).
[0121]
Although FIGS. 15(A) and 15(B) illustrate the two split
core units 35, each of the insulators 40 of all the split core
units 35 of the stator 3 has the convex portion 401 and the
15 concave portion 402. Thus, when all the split core units 35 of
the stator core 30 are assembled in an annular shape, the convex
portion 401 of each split core unit 35 is engaged with the
concave portion 402 of the adjacent split core unit 35.
[0122]
20 This makes it possible to temporarily fix the split core
units 35 in a state where the split core units 35 are assembled
in an annular shape and to handle the split core units 35
integrally. That is, in the manufacturing process of the stator
3, an operation to place the split core units 35 in the mold 200
25 and other operations can be performed easily.
[0123]
The convex portion 401 and the concave portion 402 are
desirably engaged each other with some clearance therebetween.
This is in order not to prevent the tip ends 32a of the teeth 32
30 from contacting the outer circumferential surface of the center
shaft 205 when the split core units 35 are placed in the mold
200.
[0124]
Each of the convex portion 401 and the concave portion 402
35 has a circular shape in a plane orthogonal to the axial
direction in this example, but may have any other shape as long
as the convex portion 401 is engaged with the concave portion
402.
30
5 [0125]
The convex portion 401 and the concave portion 402 may be
provided in only one of the flange portions 42a and 42b
illustrated in FIG. 8(A) or may be provided in both of the
flange portions 42a and 42b.
10 [0126]
The convex portion 401 and the concave portion 402 may be
provided not only on the flange portion 42, but may also be
provided on the wall portion 41. Further, the convex portion
401 and the concave portion 402 are not necessarily provide on
15 the insulator 40, but may be provided on any resin component
attached to the split core 33.
[0127]
The stator 3 of the second embodiment is configured in a
similar manner to the stator 3 of the first embodiment except
20 for the points described above.
[0128]
In the second embodiment described above, the insulator 40
attached to each split core 33 has the convex portion 401 and
the concave portion 402. Thus, by engagement between the convex
25 portion 401 of each insulator 40 and the concave portion 402 of
its adjacent insulator 40, the plurality of split cores 33 can
be handled integrally. Thus, the manufacturing process of the
stator 3 can be simplified.
[0129]
30 Third Embodiment
Next, a third embodiment will be described. FIG. 16 is a
diagram illustrating a stator 3A of the third embodiment
together with the center shaft 205 of the mold 200.
[0130]
35 The stator 3A of the third embodiment has a ring-shaped
outer circumference holding member 90 on the outer side of the
stator core 30 in the radial direction. The outer circumference
holding member 90 holds the split cores 33, which are arranged
31
5 in an annular shape around the center shaft 205 of the mold 200,
from outside in the radial direction.
[0131]
The outer circumference holding member 90 functions to
press the split cores 33 against the center shaft 205. This
10 makes it possible to prevent the misalignment of each split core
33 during molding.
[0132]
The outer circumference holding member 90 is composed of a
material that has a lower modulus of elasticity than that of the
15 electromagnetic steel sheet of the split core 33, i.e., a
material that is more elastically deformable than the
electromagnetic steel sheet. Specifically, the outer
circumference holding member 90 is composed of an elastic
material such as rubber, for example. Thus, the outer
20 circumference holding member 90 can be attached to the outside
of the split cores 33 in a state where the outer circumference
holding member 90 is pressed and expanded. The split cores 33
can be pressed toward the center shaft 205 using an elastic
force of the outer circumference holding member 90.
25 [0133]
The stator 3A of the third embodiment is configured in a
similar manner to the stator 3 of the first embodiment except
for the points described above.
[0134]
30 As described in the second embodiment, the insulator 40
may be provided with the convex portion 401 and the concave
portion 402 (FIG. 15).
[0135]
The stator 3A of the third embodiment has the outer
35 circumference holding member 90 that covers the split cores 33
from outside in the radial direction as described above. Thus,
each split cores 33 of the stator core 30 can be pressed against
the center shaft 205 of the mold 200, and the misalignment of
32
5 each split core 33 during molding can be effectively prevented.
[0136]
Fourth Embodiment
FIG. 17 is a sectional view illustrating a rotor 2A of a
fourth embodiment. The rotors 2 of the above-described first to
10 third embodiments are of the consequent-pole type having the
magnet magnetic poles and the virtual magnetic poles. In
contrast, the rotor 2A of the fourth embodiment is of a nonconsequent-pole type in which all the magnetic poles are formed
of magnet magnetic poles.
15 [0137]
The rotor 2A includes a rotor core 20A having a
cylindrical shape about the axis C1. The rotor core 20A is
formed of a plurality of stacking elements that are stacked in
the axial direction and integrally fixed together by crimping,
20 welding, bonding, or the like. The stacking elements are, for
example, electromagnetic steel sheets, each having a thickness
of 0.1 mm to 0.7 mm. The rotor core 20A has a central hole at
its center in the radial direction, and the rotation shaft 11 is
fixed to the center hole.
25 [0138]
A plurality of magnet insertion holes 21 are formed along
an outer circumference of the rotor core 20A. The magnet
insertion holes 21 are arranged at equal intervals in the
circumferential direction. The shape of each magnet insertion
30 hole 21 is as described in the first embodiment. The flux
barrier 22 is formed on each side of the magnet insertion hole
21 in the circumferential direction. The number of magnet
insertion holes 21 is ten in this example, but is not limited to
ten.
35 [0139]
The magnet 23 is inserted in each magnet insertion hole 21.
The magnet 23 is in the form of a flat plate and has a
rectangular cross-sectional shape in a plane orthogonal to the
33
5 axial direction. The material and shape of the magnet 23 are as
described in the first embodiment.
[0140]
The magnets 23 adjacent in the circumferential direction
are disposed so that opposite magnetic poles face the outer
10 circumference side of the rotor core 20A. Thus, all the
magnetic poles of the rotor 2A are formed of the magnets 23. In
this example, the rotor 2A has ten magnets 23, and the number of
magnetic poles of the rotor 2A is ten.
[0141]
15 The non-consequent-pole rotor 2A has more magnets 23 than
the consequent-pole rotor 2, but has an advantage that vibration
and noise are less likely to occur.
[0142]
The motor of the fourth embodiment is configured in a
20 similar manner to the motor 1 of the first embodiment except
that the rotor 2A is of the non-consequent-pole type. The nonconsequent-pole rotor 2A of the fourth embodiment may be
combined with the stator 3 described in the second or third
embodiment.
25 [0143]
Even when the non-consequent-pole rotor 2A is used as
described above, the use of the stator 3 of any one of the first
to third embodiments makes the air gap between the rotor 2A and
the stator 3 uniform in the circumferential direction, and thus
30 vibration and noise can be reduced.
[0144]
(Air Conditioner)
Next, an air conditioner to which the motor 1 of each of
the above-described embodiments is applicable will be described.
35 FIG. 18(A) is a diagram illustrating the configuration of an air
conditioner 500 to which the motor 1 of the first embodiment is
applied. The air conditioner 500 includes an outdoor unit 501,
an indoor unit 502, and a refrigerant pipe 503 connecting these
34
5 units 501 and 502.
[0145]
The outdoor unit 501 includes an outdoor fan 510 which is,
for example, a propeller fan. The indoor unit 502 includes an
indoor fan 520 which is, for example, a cross flow fan. The
10 outdoor fan 510 has the impeller 505 and a motor 1A that drives
the impeller 505. The indoor fan 520 includes an impeller 521
and a motor 1B that drives the impeller 521. Each of the motors
1A and 1B is constituted by the motor 1 described in the first
embodiment. FIG. 18(A) also illustrates a compressor 504 that
15 compresses a refrigerant.
[0146]
FIG. 18(B) is a sectional view illustrating the outdoor
unit 501. The motor 1A is supported by a frame 509 disposed in
a housing 508 of the outdoor unit 501. The impeller 505 is
20 attached to the rotation shaft 11 of the motor 1 via a hub 506.
[0147]
In the outdoor fan 510, the rotation of the rotor 2 of the
motor 1A causes the impeller 505 to rotate and blow air to the
outside of a room. During a cooling operation of the air
25 conditioner 500, heat is released when the refrigerant
compressed in the compressor 504 is condensed in a condenser,
and this heat is released to the outside of the room by airflow
of the outdoor fan 510.
[0148]
30 In the indoor fan 520 (FIG. 18(A)), the rotation of the
rotor 2 of the motor 1B causes the impeller 521 to rotate and
blow air to the inside of the room. During the cooling
operation of the air conditioner 500, the refrigerant removes
heat from the air as it evaporates in an evaporator, and the air
35 is blown into the room by airflow of the indoor fan 520.
[0149]
In the motor 1 of the first embodiment described above,
vibration and noise are reduced. Thus, the quietness of the air
35
5 conditioner 500 can be improved by constituting the motors 1A
and 1B using the motor 1 of the first embodiment.
[0150]
Each of the motors 1A and 1B is constituted by the motor 1
of the first embodiment in this example, but it is sufficient
10 that at least one of the motors 1A and 1B is constituted by the
motor 1. Alternatively, the motor of any one of the second to
fourth embodiments may be used as the motor 1A, the motor 1B or
both.
[0151]
15 The motor 1 described in each embodiment can be mounted on
any electric apparatuses other than the fan of the air
conditioner.
[0152]
Although the desirable embodiments have been specifically
20 described above, various modifications or changes can be made to
those embodiments without departing from the scope of the
present disclosure.
DESCRIPTION OF REFERENCE CHARACTERS
[0153]
25 1, 1A, 1B motor; 2, 2A rotor; 3, 3A stator; 5 mold
stator; 6 circuit board; 11 rotation shaft; 20, 20A rotor
core; 21 magnet insertion hole; 23 magnet; 25 resin part; 30
stator core; 31 core back; 31A core-back part; 32 tooth; 32a
tip end; 33 split core; 33a crimping portion; 35 split core
30 unit; 40 insulator (resin component); 41, 41a, 41b wall
portion; 42, 42a, 42b flange portion; 42c protrusion (exposed
portion); 43 body portion; 45 coil; 50 mold resin part; 51
outer circumferential portion; 52 gap resin part; 53 in-slot
resin portion; 54 surface resin portion; 55 recess; 90 outer
35 circumference holding member; 200 mold; 201 upper mold; 202
lower mold; 204 cavity; 205 center shaft; 206 recess; 207
contact surface; 208, 209 positioning pin; 210 runner; 211
gate; 212 rib; 401 convex portion; 402 concave portion; 412
36
5 tapered surface (exposed portion); 421 positioning surface;
500 air conditioner; 501 outdoor unit; 502 indoor unit; 503
refrigerant pipe; 504 compressor; 505 impeller; 510 outdoor
fan; 520 indoor fan; 521 impeller; G core-back gap; S slot
opening.
37
5 WE CLAIM:
1. A stator comprising:
a stator core having a core back in an annular shape about
an axis; and
10 a mold resin part surrounding the stator core from outside
in a radial direction about the axis, the mold resin part being
nonmagnetic,
wherein the stator core has a core-back gap passing in the
radial direction through at least a part of the core back in a
15 circumferential direction about the axis, and
wherein the mold resin part reaches an inner side of the
core back in the radial direction from an outer side of the core
back in the radial direction through the core-back gap.
20 2. The stator according to claim 1, wherein the stator core
has at least two split cores,
wherein each of the at least two split cores has a coreback part divided by the core-back gap and a tooth extending
inward in the radial direction from the core-back part, a coil
25 being wound around the tooth,
wherein a slot in which the coil is housed is formed
between two split cores of the at least two split cores that are
adjacent in the circumferential direction, and
wherein the mold resin part extends from the core-back gap
30 to an inside of the slot.
3. The stator according to claim 2, wherein the slot has a
slot opening on an inner side in the radial direction, and
wherein the mold resin part has a recess in the slot
35 opening.
4. The stator according to claim 2 or 3, wherein a resin
component is attached to each of the at least two split cores,
38
5 and
wherein the resin component has an exposed portion which
is exposed from the mold resin part.
5. The stator according to claim 4, wherein the exposed
10 portion has a support surface facing in the circumferential
direction.
6. The stator according to claim 4, wherein the exposed
portion has a contact surface facing in the radial direction.
15
7. The stator according to claim 6, wherein the contact
surface is inclined with respect to the axis.
8. The stator according to any one of claims 4 to 7, wherein
20 the resin component has a convex portion and a concave portion,
and
Wherein, of the two split cores, a convex portion of the
resin component of one split core is engaged with a concave
portion of the resin component of the other split core.
25
9. The stator according to any one of claims 1 to 8, wherein
a gate mark is formed on an outer circumferential surface of the
mold resin part.
30 10. The stator according to any one of claims 1 to 9, wherein
a volume V1 of a portion of the mold resin part that is located
on an outer side in the radial direction with respect to the
stator core is larger than a volume V2 of a portion of the mold
resin part that is located on an inner side in the radial
35 direction with respect to the stator core.
11. The stator according to any one of claims 1 to 10, further
comprising an outer circumference holding member to hold the
39
5 stator core from outside in the radial direction.
12. The stator according to claim 11, wherein a modulus of
elasticity of the outer circumference holding member is lower
than a modulus of elasticity of the stator core.
10
13. The stator according to claim 11 or 12, wherein the outer
circumference holding member is composed of a rubber.
14. A motor comprising:
15 the stator according to any one of claims 1 to 13; and
a rotor disposed inside the stator in the radial direction.
15. The motor according to claim 14, wherein the rotor has a
rotor core and a magnet attached to the rotor core, the magnet
20 forming a first magnetic pole, a part of the rotor core forming
a second magnetic pole.
16. The motor according to claim 14, wherein the rotor has a
rotor core and a first magnet and a second magnet that are
25 attached to the rotor core, the first magnet forming a first
magnetic pole, the second magnet forming a second magnetic pole.
17. A fan comprising:
the motor according to any one of claims 14 to 16; and
30 an impeller rotated by the motor.
18. An air conditioner comprising an outdoor unit and an
indoor unit connected to the outdoor unit via a refrigerant pipe,
wherein at least one of the outdoor unit and the indoor
35 unit has the fan according to claim 17.
19. A manufacturing method of a stator, the manufacturing
method comprising the steps of:
40
5 placing a stator core in a mold, the stator core having a
core back in an annular shape about an axis, the core back
having a core-back gap passing in a radial direction about the
axis through at least a part of the core back in a
circumferential direction about the axis; and
10 molding the stator core integrally with a mold resin,
wherein in the step of placing the stator core in the mold,
the core back is brought into contact with a positioning surface
of the mold, and
wherein in the step of molding the stator core integrally
15 with the mold resin, the mold resin is made to reach an inner
side of the core back in the radial direction from an outer side
of the core back in the radial direction through the core-back
gap.
20 20. The manufacturing method of a stator according to claim 19,
wherein in the step of placing the stator core in the mold, the
core back is positioned in the circumferential direction with
respect to the mold by a protrusion provided in the mold.
21. The manufacturing method of a stator according to claim 19
or 20, wherein in the step of molding the stator core integrally
with the mold resin, the core back is pressed inward in the
radial direction by a positioning portion provided in the mold.