DESCRIPTION
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
ELECTRIC-MOTOR STATOR, COMPRESSOR, AND REFRIGERATION CYCLE
APPARATUS;
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
Title of Invention
ELECTRIC-MOTOR STATOR, COMPRESSOR, AND REFRIGERATION CYCLE
APPARATUS
5
Technical Field
[0001]
The present disclosure relates to an electric-motor stator, a compressor, and a
refrigeration cycle apparatus, particularly to a structure of an electric-motor stator.
10 Background Art
[0002]
In general, an electric-motor stator to be included in a device such as a
compressor includes a stator core, coils, and an insulator that insulates the stator core
and the coils from each other. The stator core includes a cylindrical back yoke and a
15 plurality of teeth extending from the back yoke toward the center axis. The coils are
wound around the respective teeth with the insulator in between and are positioned in
slots defined between the teeth that are adjacent to one another. The electric-motor
stator is desired to have an increased space factor (winding density) of the coils for
improved performance of the electric motor. Hence, in a known technique, dead
20 spaces in slots are minimized by employing a stator core including a plurality of arcshaped core segments. Furthermore, when winding is performed, the plurality of core
segments are spread out to be arranged in a line so that the slots are expanded for
easy winding (see Patent Literature 1, for example). According to Patent Literature 1,
with the stator core being spread out, respective outer peripheral regions of back yokes
25 of the adjacent core segments are joined to one another at peripheral-direction end
portions thereof, whereas V-shaped gaps are produced between respective inner
peripheral regions of the core segments at the joints therebetween. When the plurality
of core segments are brought into an annular shape after winding is complete, the gaps
in the inner peripheral regions at the joints are closed. The electric-motor stator
30 disclosed by Patent Literature 1 includes insulators, which are winding frames and slot
3
insulators. The winding frames are made of an insulating resin material and provided
at coil ends. The slot insulators include respective folds in respective areas that face
the joints between the back yokes (the areas are each hereinafter referred to as jointcovering part). The folds facilitate the insulation between the stator core and the coils.
5 To secure a wider area for winding, a film-type insulator is employed as the slot
insulator. In the stator disclosed by Patent Literature 1, when the plurality of core
segments are brought into the annular shape, the folds project inward, that is, toward
the center axis, so that the slot insulators are prevented from being caught between the
back yokes of the adjacent core segments. The folds each extend in the axial direction
10 from one end to the other end of a corresponding one of the joint-covering parts that
cover the joints between the back yokes.
Citation List
Patent Literature
[0003]
15 Patent Literature 1: Japanese Unexamined Patent Application Publication No. 9-
191588
Summary of Invention
Technical Problem
[0004]
20 As disclosed in Patent Literature 1, while winding is being performed on the teeth,
each winding nozzle moves through the slots between the teeth, above the teeth, and
below the teeth. Therefore, according to Patent Literature 1 in which the slot insulators
include the folds each extending from one end to the other end of the joint-covering part
in the axial direction, when the winding nozzle changes the direction of movement
25 thereof at the end of each tooth during winding, the fold in the relevant joint-covering
part may be caught between wire lines. If the slot insulator is caught between wire
lines, the arrangement of the wire lines is disturbed. Consequently, the space factor
(winding density) of the coil in that slot is reduced.
[0005]
4
To avoid such wrapping of the slot insulator, the joint-covering part of each of the
slot insulators may be made flat with no fold. In such a case, however, no structure is
provided for maintaining the shape of the joint-covering part when the stator core is
spread out. Therefore, the shape of the joint-covering part is unstable. Consequently,
5 wrapping of the slot insulator may occur, leading to disarray in the windings of wire lines
and a reduction in the space factor of the coil in the slot.
[0006]
The present disclosure is to solve the above problem and to provide an electricmotor stator, a compressor, and a refrigeration cycle apparatus each having a low
10 probability that the space factor of coils may be reduced because of disarray in the
windings of wire lines.
Solution to Problem
[0007]
An electric-motor stator of one embodiment of the present disclosure includes a
15 stator core including a plurality of core segments that are annularly joined to one
another, the core segments each including an arc-shaped back yoke and a tooth, the
tooth extending from a peripheral-direction center of an inner surface of the back yoke
toward a center axis; coils wound around the respective teeth of the core segments; and
an insulator insulating the core segments and the coils from each other. The stator
20 core has slots each of which is provided between adjacent two of the teeth and in which
the coils are positioned. The insulator includes slot insulators positioned in the
respective slots and each being continuous in such a manner as to cover a
corresponding one of slot inner peripheral walls of the stator core. The slot insulators
each include a joint-covering part that covers a joint where two of the back yokes are
25 joined to each other, the joint forming a portion of the corresponding slot inner
peripheral wall. The joint-covering part has a projection projecting toward the center
axis and provided only in a central area of the joint-covering part in an axial direction, or
projections projecting radially outward and provided only in end areas of the jointcovering part that are on two respective sides in the axial direction.
5
A compressor of another embodiment of the present disclosure includes an
electric motor including the above electric-motor stator, and a rotor that is rotatable
relative to the electric-motor stator; and a compressing element configured to be driven
by the electric motor and to compress refrigerant.
5 A refrigeration cycle apparatus of still another embodiment of the present
disclosure includes a refrigerant circuit in which the above compressor, a first heat
exchanger, a decompressor, and a second heat exchanger are connected to one
another by a refrigerant pipe.
Advantageous Effects of Invention
10 [0008]
According to each of the above embodiments of the present disclosure, the jointcovering part has the projection projecting toward the center axis and provided only in
the central area of the joint-covering part in the axial direction, or the projections
projecting radially outward and provided only in the end areas of the joint-covering part
15 that are on the two respective sides in the axial direction. In either case, the jointcovering part of the slot insulator has a projection. Therefore, the shape of the jointcovering part is stabilized. Furthermore, in either case, the joint-covering part of the
slot insulator has no structure projecting into the slot in the end areas thereof on the two
respective sides in the axial direction. Therefore, the probability of wrapping of the slot
20 insulator during winding is reduced. Accordingly, the electric-motor stator, the
compressor, and the refrigeration cycle apparatus each have a low probability that the
space factor of the coils may be reduced because of disarray in the windings of wire
lines.
Brief Description of Drawings
25 [0009]
[Fig. 1] Fig. 1 is a perspective view of an electric-motor stator according to
Embodiment 1, illustrating a configuration thereof.
[Fig. 2] Fig. 2 is a plan view of the stator illustrated in Fig. 1, illustrating a
configuration thereof.
6
[Fig. 3] Fig. 3 is a perspective view of one of core segments included in the stator
illustrated in Fig. 1, as seen from the inner side thereof.
[Fig. 4] Fig. 4 is a perspective view of the core segment included in the stator
illustrated in Fig. 1, as seen from the outer side thereof.
5 [Fig. 5] Fig. 5 illustrates a section of a part of the stator illustrated in Fig. 1.
[Fig. 6] Fig. 6 is a perspective view of one of stator segments included in the
stator illustrated in Fig. 1, as seen from the inner side thereof.
[Fig. 7] Fig. 7 illustrates the stator illustrated in Fig. 5 that is spread out before
winding is performed.
10 [Fig. 8] Fig. 8 is a perspective view of adjacent two of the core segments of the
stator illustrated in Fig. 1 to which an insulator is attached and that are spread out
before winding is performed, as seen from the inner side thereof.
[Fig. 9] Fig. 9 is a perspective view of one of the adjacent core segments 10
illustrated in Fig. 8, as seen from the outer side thereof.
15 [Fig. 10] Fig. 10 illustrates a configuration of a part of the stator illustrated in Fig.
1 that is spread out before winding is performed, as seen in a direction from teeth
thereof toward the outer side.
[Fig. 11] Fig. 11 illustrates a section of the stator illustrated in Fig. 10, taken along
line A-A.
20 [Fig. 12] Fig. 12 illustrates a section of the stator illustrated in Fig. 10, taken along
line B-B.
[Fig. 13] Fig. 13 is a cross-sectional view of the stator segment illustrated in Fig.
6.
[Fig. 14] Fig. 14 illustrates, in perspective view, a positional relationship between
25 the stator illustrated in Fig. 1 and winding nozzles while winding is being performed on
the stator.
[Fig. 15] Fig. 15 illustrates a configuration of a part of the stator and the winding
nozzles illustrated in Fig. 14, as seen from below the stator segments.
[Fig. 16] Fig. 16 illustrates a longitudinal section of a compressor including the
30 stator illustrated in Fig. 1.
7
[Fig. 17] Fig. 17 illustrates a refrigerant circuit of a refrigeration cycle apparatus
including the compressor illustrated in Fig. 16.
[Fig. 18] Fig. 18 illustrates a configuration of a part of a stator according to
Embodiment 2 that is spread out before winding is performed, as seen in a direction
5 from teeth thereof toward the outer side.
[Fig. 19] Fig. 19 illustrates a section of the stator illustrated in Fig. 18, taken along
line C-C.
[Fig. 20] Fig. 20 illustrates a section of the stator illustrated in Fig. 18, taken along
line D-D.
10 Description of Embodiments
[0010]
Embodiments of the present disclosure will now be described with reference to
the drawings. In the drawings, the same or equivalent elements are denoted by the
same reference signs, and description thereof is omitted or simplified as appropriate.
15 The shape, size, arrangement, and other factors of the elements illustrated in the
drawings can be changed as appropriate.
[0011]
Embodiment 1
(Stator)
20 Fig. 1 is a perspective view of an electric-motor stator according to Embodiment
1, illustrating a configuration thereof. Fig. 2 is a plan view of the stator illustrated in
Fig. 1, illustrating a configuration thereof. As illustrated in Fig. 1, a stator 34 has a
cylindrical shape. As illustrated in Fig. 2, the stator 34 includes a plurality of stator
segments 50, which are arranged annularly in plan view. As to be described below, the
25 stator 34 is combined with a rotor into an electric motor 100 (Fig. 16). The rotor is
rotatable relative to the stator 34. Fig. 1 illustrates a center axis O, which is defined for
the stator 34. Hereinafter, a configuration of the stator 34 will be described, defining
the direction of the center axis O (the direction of arrow Z) as the top-bottom direction of
the stator 34.
30 [0012]
8
(Stator Segment 50)
Fig. 1 illustrates an example in which nine stator segments 50 are annularly
joined to one another, thereby forming the stator 34. As illustrated in Fig. 1, the stator
segments 50 each include a core segment 10; an insulator 8, which is provided on the
5 core segment 10; and a coil 5, which is formed of a conductive wire wound around the
core segment 10.
[0013]
(Core Segment 10)
Fig. 3 is a perspective view of one of the core segments included in the stator
10 illustrated in Fig. 1, as seen from the inner side thereof. Fig. 4 is a perspective view of
the core segment included in the stator illustrated in Fig. 1, as seen from the outer side
thereof. As illustrated in Fig. 3, the core segment 10 includes a plurality of iron core
pieces 1. The iron core pieces 1 are magnetic plates and are obtained by, for
example, punching of an electromagnetic steel plate, which is a soft magnetic material,
15 with a die. The plurality of iron core pieces 1 are stacked in the top-bottom direction
(the direction of arrow Z) and are integrated with one another by a technique such as
swaging. Thus, the core segment 10 is obtained as a block with a certain thickness in
the top-bottom direction (the direction of arrow Z). Hereinafter, the plurality of core
segments 10 included in the stator 34 is also collectively referred to as stator core.
20 [0014]
The core segments 10 each include an arc-shaped back yoke 10a, which forms
an outer peripheral portion of the stator 34; a tooth 10b, which extends from an inner
surface 10ai of the back yoke 10a toward the center axis O (Fig. 1); and shoes 10c,
which are provided at the two respective peripheral-direction ends of a distal portion
25 10b1 of the tooth 10b. The back yoke 10a has an outer peripheral surface 10ao, which
has an arc shape in plan view as illustrated in Fig. 4; the inner surface 10ai, which has a
linear shape in plan view as illustrated in Fig. 3; and two lateral surfaces 10as, which
connect the outer peripheral surface 10ao (Fig. 4) and the inner surface 10ai to each
other at the two respective peripheral-direction ends. Each core segment 10 is joined
9
to other core segments 10 that are adjacent thereto, at the peripheral-direction ends of
the back yokes 10a thereof.
[0015]
Fig. 5 illustrates a section of a part of the stator 34 illustrated in Fig. 1. As
5 illustrated in Fig. 5, the adjacent stator segments 50 are joined to one another at the
lateral surfaces 10as of the back yokes 10a in regions thereof near the outer peripheral
surfaces 10ao. Hereinafter, the regions where the back yokes 10a of the adjacent core
segments 10 are joined to one another are each also referred to as joint.
[0016]
10 The tooth 10b extends from the peripheral-direction center of the inner surface
10ai of the back yoke 10a toward the center axis O. Fig. 3 illustrates an example in
which the thickness of the tooth 10b in the peripheral direction is constant from a portion
thereof close to the back yoke 10a to a portion thereof close to the center axis O (Fig.
1), and the inner surface 10ai of the back yoke 10a perpendicularly abuts lateral
15 surfaces 10bs of the tooth 10b. While Embodiment 1 relates to a case where the inner
surface 10ai of the back yoke 10a perpendicularly abuts the lateral surfaces 10bs of the
tooth 10b, the angle between the inner surface 10ai and the lateral surfaces 10bs does
not necessarily need to be perpendicular.
[0017]
20 As illustrated in Fig. 3, the shoes 10c each have a tapered shape defined by an
inner surface 10ci, which faces toward the center axis O; and an outer surface 10co
(Fig. 4), which faces toward the back yoke 10a. The inner surface 10ci of the shoe 10c
and an inner surface 10bi of the tooth 10b are smoothly continuous with each other to
form an inner surface 10i of the core segment 10. The inner surface 10i of the core
25 segment 10 has an arc shape.
[0018]
When the plurality of stator segments 50 are in an annular shape as illustrated in
Fig. 2, each of the two lateral surfaces 10as of the back yoke 10a of one core segment
10, illustrated in Fig. 4, is in contact with one of the lateral surfaces 10as of the back
30 yoke 10a of either of other two core segments 10 that are adjacent to the one core
10
segment 10. Hereinafter, the state where the plurality of stator segments 50 are in an
annular shape is also referred to as the closed state of the stator core.
[0019]
As illustrated in Fig. 2, the stator 34 has slots 6 between the adjacent core
5 segments 10. The coils 5 are wound around the respective teeth 10b (Fig. 4) with the
insulator 8 in between, and are positioned in the slots 6. That is, the slots 6 are each a
space provided between adjacent two of the core segments 10 and enclosed by the
lateral surfaces 10bs of the teeth 10b that face each other, the outer surfaces 10co of
the shoes 10c that face each other, and the inner surfaces 10ai of the back yokes 10a
10 that are adjacent to each other. Hereinafter, the set of the foregoing surfaces that
define each of the slots 6 between the adjacent core segments 10 is also referred to as
slot inner peripheral wall.
[0020]
(Coil 5)
15 Fig. 6 is a perspective view of one of the stator segments 50 included in the stator
illustrated in Fig. 1, as seen from the inner side thereof. As illustrated in Fig. 6, the coil
5 is a conductive wire that is formed of a core wire serving as a conductor, and an
insulating covering that covers the core wire. The core wire is made of, for example,
copper, aluminum, or a conductive alloy. The conductive wire forming the coil 5 is
20 wound by a plurality of turns around the tooth 10b of the core segment 10 with the
insulator 8 in between. The coil 5 has an annular shape elongated in the top-bottom
direction (the direction of arrow Z). The coil 5 that is a conductive wire wound around
the tooth 10b has magnetic poles, accordingly. While a current is flowing through the
conductive wire forming the coil, magnetic flux is generated around the tooth 10b. The
25 wire wound by a plurality of turns around the tooth 10b (Fig. 3) between the back yoke
10a and the shoes 10b forms a plurality of layers at the upper end of the stator segment
50. Each of the layers includes a plurality of wire lines that are arranged in a row.
[0021]
(Insulator 8)
11
Fig. 7 illustrates the stator 34 illustrated in Fig. 5 that is spread out before winding
is performed. In the process of manufacturing the stator 34, winding is performed with
the plurality of core segments 10 being arranged in a line as illustrated in Fig. 7.
Hereinafter, the state where the plurality of core segments 10 are arranged in a line is
5 also referred to as a spread state. In the spread state, the adjacent core segments 10
are joined to one another at joints 10r, whereas V-shaped gaps 10g are produced
between the lateral surfaces 10as of the back yokes 10a in areas near the inner
surfaces 10ai.
[0022]
10 Fig. 8 is a perspective view of adjacent two of the core segments 10 of the stator
illustrated in Fig. 1 to which the insulator 8 is attached and that are spread out before
winding is performed, as seen from the inner side thereof. Fig. 9 is a perspective view
of one of the adjacent core segments 10 illustrated in Fig. 8, as seen from the outer side
thereof. As illustrated in Fig. 8, the insulator 8 insulates the core segments 10, which
15 are made of a material such as iron, and the coils 5, which are made of a material such
as copper, from each other. The insulator 8 includes pairs of end-face insulators 4 and
slot insulators 7. The end-face insulators 4 in each pair are provided for a
corresponding one of the core segments 10 and are attached to respective end faces of
the core segment 10 that are located on the two respective sides in the axial direction
20 (the direction of arrow Z). The slot insulators 7 are positioned in the respective slots 6
of the stator core and are each continuous in such a manner as to cover a
corresponding one of the slot inner peripheral walls.
[0023]
Fig. 10 illustrates a configuration of a part of the stator illustrated in Fig. 1 that is
25 spread out before winding is performed, as seen in a direction from teeth thereof toward
the outer side. Fig. 11 illustrates a section of the stator illustrated in Fig. 10, taken
along line A-A. Fig. 12 illustrates a section of the stator illustrated in Fig. 10, taken
along line B-B. Referring to Figs. 7 to 12, configurations of the slot insulators 7 and the
pairs of end-face insulators 4 will now be described.
30 [0024]
12
(Slot Insulator 7)
As illustrated in Fig. 7, the slot insulators 7 are provided for the respective slots 6
of the stator 34. Each of the slot insulators 7 has a thickness that provides a
satisfactory distance for insulation between the coil 5 and the slot inner peripheral wall
5 that is formed by adjacent two of the core segments 10, thereby insulating the two from
each other.
[0025]
As illustrated in Fig. 8, the slot insulator 7 provided in each slot 6 is a sheet of
insulating film. The slot insulator 7 may be, for example, a PET (polyethylene
10 terephthalate) film.
[0026]
As illustrated in Fig. 7, the slot insulator 7 seamlessly covers the slot inner
peripheral wall formed by adjacent two of the core segments 10 that define the slot 6.
Accordingly, the slot insulator 7 covers the joint 10r between the adjacent core
15 segments 10. The slot insulator 7 includes a back-yoke-covering portion 7a, which
covers adjacent two of the back yokes 10a forming portions of the slot inner peripheral
wall; two tooth-covering portions 7b, which cover the two respective teeth 10b; and two
shoe-covering portions 7c, which cover the two respective shoes 10c. Hereinafter, an
area of the back-yoke-covering portion 7a that is in the peripheral-direction center and
20 covers the joint 10r between the adjacent back yokes 10a is also referred to as jointcovering part 70 (see Fig. 10).
[0027]
As illustrated in Fig. 8, in the spread state where the adjacent back yokes 10a are
arranged in a line, each back-yoke-covering portion 7a is positioned by corresponding
25 pairs of end-face insulators 4 such that an upper end area 7a1 and a lower end area
7a2 thereof extend along the inner surfaces 10ai of corresponding ones of the back
yokes 10a. Note that the pairs of end-face insulators 4 provide no structure that
directly holds the joint-covering part 70 of the slot insulator 7.
[0028]
13
As illustrated in Fig. 12, the joint-covering part 70 of the back-yoke-covering
portion 7a of the slot insulator 7 that covers the joint 10r has a projection 71, which
extends in the axial direction (the direction of arrow Z) and projects toward the center
axis O. As illustrated in Fig. 10, the projection 71 in the joint-covering part 70 of the
5 slot insulator 7 has a predetermined length in the axial direction (the direction of arrow
Z). The projection 71 projecting toward the center axis O is formed only in a central
area 70c, in the axial direction (the direction of arrow Z), of the joint-covering part 70 of
the back-yoke-covering portion 7a and in neither an upper end area 70a nor a lower end
area 70b of the joint-covering part 70. As illustrated in Fig. 11, when the stator core is
10 in the spread state, the upper end area 70a and the lower end area 70b of the jointcovering part 70, that is, areas of the joint-covering part 70 that are at the two respective
ends in the axial direction (the direction of arrow Z), are substantially flat along the inner
surfaces 10ai of the back yokes 10a.
[0029]
15 Since the projection 71 is provided in the central area 70C of the joint-covering
part 70 in the axial direction, the shape of the joint-covering part 70 is stabilized. On
the other hand, the end areas of the joint-covering part 70 each have no structure
projecting into the slot 6. Therefore, the probability of wrapping of the slot insulator
during winding is reduced. Consequently, the probability of disarray in the windings of
20 wire lines is reduced.
[0030]
While Fig. 11 illustrates an example in which the joint-covering part 70 is
substantially flat in the end areas on the two respective sides in the axial direction, the
joint-covering part 70 may have another projection projecting radially outward in each of
25 the end areas thereof. In the closed state of the stator core as illustrated in Fig. 1,
different pairs of end-face insulators 4 attached to the respective stator segments 50
that are adjacent to each other are spaced apart from each other on the outer peripheral
side relative to the back-yoke-covering portion 7a. Therefore, even if the joint-covering
part 70 has another projection projecting radially outward at each of the end areas
14
thereof, such a projection does not hinder the process of bringing the stator core into an
annular shape after winding is complete.
[0031]
(Pair of End-Face Insulators 4)
5 As illustrated in Fig. 8, each core segment 10 is provided with one pair of endface insulators 4. The pair of end-face insulators 4 are an upper end-face insulator 2,
which is attached to the upper end face of the core segment 10; and a lower end-face
insulator 3, which is attached to the lower end face of the core segment 10. The upper
end-face insulator 2 has a thickness that provides a satisfactory distance for insulation
10 between the coil 5 and the upper end face of the core segment 10, thereby insulating
the two from each other. The lower end-face insulator 3 has a thickness that provides
a satisfactory distance for insulation between the coil 5 and the lower end face of the
core segment 10, thereby insulating the two from each other. The pair of end-face
insulators 4 attached to the core segment 10 also serve as winding frames for the coil 5.
15 [0032]
(Upper End-Face Insulator 2)
The upper end-face insulator 2 includes an outer flange 2a; an inner flange 2b,
which is provided on the radially inner side relative to the outer flange 2a; and a toothend-face-covering portion 2c, which extends between the outer flange 2a and the inner
20 flange 2b. The upper end-face insulator 2 further includes a stepped portion 2d, which
connects the tooth-end-face-covering portion 2c and the outer flange 2a to each other;
and an inclined portion 2e (Fig. 9), which connects the tooth-end-face-covering portion
2c and the inner flange 2b to each other. The outer flange 2a and the inner flange 2b
regulate the arrangement of the wire lines in upper ones of a plurality of wire layers
25 forming the coil 5. The stepped portion 2d and the inclined portion 2e (Fig. 9) regulate
the arrangement of the wire lines in lower ones of the plurality of wire layers forming the
coil 5.
[0033]
The outer flange 2a has a cuboidal shape. The lower surface of the outer flange
30 2a is in contact with the upper surface of the back yoke 10a in an area close to the
15
center axis O. The outer flange 2a is positioned on the back yoke 10a such that the
inner surface of the outer flange 2a is flush with the inner surface 10ai (Fig. 3) of the
back yoke 10a. The inner surface of the outer flange 2a has lower areas that are
located on the two respective peripheral-direction sides thereof and along each of which
5 an area, specifically, the upper end area 7a1, of the back-yoke-covering portion 7a of a
corresponding one of the slot insulators 7 extends. The width of the outer flange 2a in
the peripheral direction is smaller than the width of the back yoke 10a in the peripheral
direction. In the stator segments 50 that are adjacent to one another, the respective
outer flanges 2a are spaced apart from one another.
10 [0034]
The inner flange 2b has a substantially cuboidal shape with an arc-shaped inner
surface 2bi, which faces toward the center axis O. The arc-shaped inner surface 2bi of
the inner flange 2b has a curvature that is substantially equal to the curvature of the
inner surface 10i of the core segment 10. The inner flange 2b is positioned on the
15 shoes 10c such that the inner surface 2bi of the inner flange 2b is flush with the inner
surface 10i of the core segment 10. The inner flange 2b has slits 2b1 in lower areas
thereof located on the two respective peripheral-direction sides. The slits 2b1 each
extend in the peripheral direction from the inclined portion 2e to a corresponding one of
the lateral surfaces of the inner flange 2b. The two peripheral-direction ends of each of
20 the slits 2b1 are open. The slits 2b1 receive areas of the shoe-covering portions 7c of
corresponding ones of the slot insulators 7. Specifically, an upper end area of each
shoe-covering portion 7c is inserted into a corresponding one of the slits 2b1 from
below, whereby the position of the upper end area of the shoe-covering portion 7c is
regulated.
25 [0035]
The tooth-end-face-covering portion 2c is connected to a lower area of the outer
flange 2a and to a lower area of the inner flange 2b. The tooth-end-face-covering
portion 2c is, for example, a U-shaped plate and includes end parts 2c1, which extend
downward on the two respective peripheral-direction sides of the tooth-end-face30 covering portion 2c. The tooth-end-face-covering portion 2c covers the upper surface
16
of the tooth 10b and upper end areas of the two respective lateral surfaces 10bs (Fig. 4)
of the tooth 10b.
[0036]
The stepped portion 2d is raised in a graded manner in a direction from the tooth5 end-face-covering portion 2c toward the outer flange 2a. That is, in the stepped
portion 2d, a tread closer to the outer flange 2a has a greater outside diameter. The
stepped portion 2d has a substantially U shape along the tooth-end-face-covering
portion 2c and includes end parts 2d1, which extend downward on the two respective
peripheral-direction sides of the stepped portion 2d.
10 [0037]
A gap is provided between each of the end parts 2d1 of the stepped portion 2d
and the inner surface of the outer flange 2a. A part of the upper end area 7a1 of the
back-yoke-covering portion 7a that abuts the tooth-covering portion 7b is positioned in
the gap and is thus pressed toward the back yoke 10a of the core segment 10.
15 Another gap is provided between each of the end parts 2d1 of the stepped portion 2d
and a corresponding one of the end parts 2c1 of the tooth-end-face-covering portion 2c.
A part of the upper end area of the tooth-covering portion 7b that abuts the back-yokecovering portion 7a is positioned in the gap and is thus pressed toward the tooth 10b of
the core segment 10. In other words, the end parts 2d1 of the stepped portion 2d each
20 press a corresponding one of the slot insulators 7 toward the core segment 10 at the
boundary between the tooth-covering portion 7b and the back-yoke-covering portion 7a.
Hereinafter, the end parts 2d1 of the stepped portion 2d are each also referred to as
pressing part.
[0038]
25 As illustrated in Fig. 9, the inclined portion 2e is inclined such that the outside
diameter thereof increases in a direction from the tooth-end-face-covering portion 2c
toward the inner flange 2b. The inclined portion 2e has a substantially U shape along
the tooth-end-face-covering portion 2c and includes end parts 2e1, which extend
downward on the two respective peripheral-direction sides of the inclined portion 2e.
30 Note that Fig. 9 illustrates an example in which the end parts 2e1 of the inclined portion
17
2e that extend downward do not reach the respective slits 2b1 in the lower areas of the
inner flange 2b so that the insertion of the shoe-covering portions 7c into the slits 2b1 is
not hindered.
[0039]
5 (Lower End-Face Insulator 3)
As illustrated in Fig. 8, the lower end-face insulator 3 has a configuration
substantially vertically symmetrical to the upper end-face insulator 2. As with the upper
end-face insulator 2, the lower end-face insulator 3 includes an outer flange 3a, an inner
flange 3b, a tooth-end-face-covering portion 3c, a stepped portion (not illustrated), and
10 an inclined portion 3e (Fig. 9). The inner flange 3b of the lower end-face insulator 3
has slits 3b1. Unlike the outer flange 2a of the upper end-face insulator 2, the outer
flange 3a of the lower end-face insulator 3 has a wiring groove 3f. The wiring groove
3f receives the terminal end of the conductive wire forming the coil 5.
[0040]
15 Fig. 13 is a cross-sectional view of the stator segment 50 illustrated in Fig. 6. In
Fig. 13, the plurality of wire lines in the coil 5 are numbered in the order of winding.
Fig. 14 illustrates, in perspective view, a positional relationship between the stator 34
illustrated in Fig. 1 and winding nozzles 20 while winding is being performed on the
stator 34. Fig. 15 illustrates a configuration of a part of the stator 34 and the winding
20 nozzles 20 illustrated in Fig. 14, as seen from below the stator segments 50. Referring
to Figs. 13 to 15, a winding process to be performed in manufacturing the stator 34 will
now be described.
[0041]
As illustrated in Fig. 14, the slot insulators 7 are attached to the respective slot
25 inner peripheral walls, and the pairs of end-face insulators 4 are attached to the end
faces of the core segments 10 on the two respective sides in the axial direction. In
such a state, the winding process is performed. In the winding process, coils 5 are
wound around the plurality of core segments 10 that are spread out to be arranged in a
line. Specifically, when the winding process is performed, the plurality of core
30 segments 10 with the insulator 8 attached thereto are held by a jig 21 or any other
18
device such that the back yokes 10a thereof are arranged in a line. The plurality of
winding nozzles 20 are positioned at regular intervals. With the plurality of core
segments 10 being held by the jig 21, coils 5 are wound around the respective teeth
10b. The plurality of winding nozzles 20 move relative to the jig 21 while keeping the
5 regular intervals therebetween, whereby conductive wires 5a fed from the respective
winding nozzles 20 are wound around the respective teeth 10b of interest. In this step,
each of the winding nozzles 20 moves through the slots 6 on both sides of the core
segment 10 of interest and above and below the core segment 10 of interest.
[0042]
10 Fig. 13 illustrates an example in which the wire starts to be wound from a position
of the upper end face of the core segment 10 that is next to the stepped portion 2d of
the upper end-face insulator 2. A first turn is formed in contact with the riser of a first
step in the stepped portion 2d of the upper end-face insulator 2. Specifically, the
conductive wire starts to be wound from a position of the tooth-end-face-covering
15 portion 2c that is next to the stepped portion 2d toward the inner flange 2b in the
direction of arrow D1, whereby a first layer of the conductive wire is formed. After a
predetermined number of wire lines are formed as the first layer, a second layer of the
conductive wire starts to be formed in the direction of arrow D2 toward the outer flange
2a. The second layer of the conductive wire is formed in such a manner as to make a
20 staggered pile in which each of the wire lines in the second layer is in contact with
adjacent two of the wire lines in the first layer. Likewise, third and subsequent layers
are formed such that the wire lines in each layer are staggered relative to the wire lines
in the layer immediately therebelow. When the winding by a predetermined number of
turns is complete, the terminal end of the conductive wire 5a is positioned in the wiring
25 groove 3f provided in the outer flange 3a of the lower end-face insulator 3.
[0043]
In the coil 5, the wire lines in lower layers, such as the first and second layers, are
positioned between the stepped portion 2d and the inclined portion 2e on the upper
end-face insulator 2. Thus, the radial positions of the wire lines in the lower layers are
30 regulated by the stepped portion 2d and the inclined portion 2e. Specifically, one of the
19
wire lines in each of the lower layers that is closest to the outer flange 2a is in contact
with a corresponding one of the risers of the stepped portion 2d, whereas one of the
wire lines in each of the lower layers that is closest to the inner flange 2b is in contact
with the inclined portion 2e. One of the wire lines in the first layer that is closest to the
5 outer flange 2a is in contact with the riser of the first step in the stepped portion 2d.
One of the wire lines in the second layer that is closest to the outer flange 2a is in
contact with the riser of a second step in the stepped portion 2d. The second step is at
a higher level than the first step and closer to the outer flange 2a than the first step.
Such a configuration reduces the probability that the wire lines in the lower layers of the
10 coil 5 may be spaced apart from one another in the radial direction. Therefore, the
wire lines in the lower layers of the coil 5 and the wire lines in the upper layers (third and
subsequent layers, for example) of the coil 5 are arranged properly.
[0044]
As illustrated in Fig. 15, the stator 34 includes the plurality of stator segments 50
15 that are divided in correspondence with the teeth 10b. Therefore, the width of the
space between adjacent ones of the teeth 10b is greater when the stator core is in the
spread state for winding than when the stator core is closed. Accordingly, the width of
each of the winding nozzles 20 can be increased so that a thicker conductive wire is
allowed to be wound around the teeth 10b.
20 [0045]
As described above, the joint-covering part 70 of each of the slot insulators 7 has
no structure projecting into the slot 6 in the end areas thereof on the two respective
sides in the axial direction, and the shape of the joint-covering part 70 is stabilized by
the projection 71. Therefore, the probability of wrapping of the slot insulator 7 during
25 winding is reduced. Thus, the proper arrangement of the wire lines is ensured.
[0046]
As illustrated in Fig. 15, when winding is performed, the back-yoke-covering
portions 7a of the slot insulators 7 extend along the inner surfaces 10ai of the back
yokes 10a. That is, the joint-covering parts 70 are positioned on the radially outer side
20
relative to the trajectory of the conductive wire 5a during winding. Therefore, the
probability of wrapping of the slot insulator 7 during winding is further reduced.
[0047]
To summarize, the electric-motor stator 34 according to Embodiment 1 includes
5 the stator core including the plurality of core segments 10 annularly joined to one
another, the coils 5, and the insulator 8 insulating the core segments 10 and the coils 5
from each other. The core segments 10 each include the arc-shaped back yoke 10a,
and the tooth 10b extending from the peripheral-direction center of the inner surface
10ai of the back yoke 10a toward the center axis O. The coils 5 are wound around the
10 respective teeth 10b of the core segments 10. The stator core has the slots 6 each of
which is provided between adjacent two of the teeth 10b and in which the coils 5 are
positioned. The insulator 8 includes the slot insulators 7 each being continuous in
such a manner as to cover a corresponding one of the slot inner peripheral walls of the
stator core. The slot insulators 7 each include the joint-covering part 70 that covers the
15 joint 10r where two of the back yokes 10a are joined to each other. The joint 10r forms
a portion of the corresponding slot inner peripheral wall. The joint-covering part 70 has
the projection 71 projecting toward the center axis O and provided only in the central
area 70c of the joint-covering part 70 in the axial direction (the direction of arrow Z).
[0048]
20 Thus, the shape of the joint-covering part 70 of each of the slot insulators 7 is
stabilized by the projection 71 provided in the central area 70c of the joint-covering part
70 in the axial direction (the direction of arrow Z). Furthermore, the joint-covering part
70 has no projecting structure in the end areas thereof on the two respective sides in
the axial direction. Such a configuration reduces the probability of wrapping of the
25 joint-covering part 70 of the slot insulator 7 that may occur when the winding nozzle 20
changes the direction of movement thereof at the end of each of the teeth 10b during
winding. Thus, the proper arrangement of wire lines is ensured. Accordingly, the
electric-motor stator 34 has a low probability that the space factor of the coils 5 may be
reduced because of disarray in the windings of wire lines.
30 [0049]
21
The insulator 8 includes the pairs of end-face insulators 4. The end-face
insulators 4 in each pair are attached to the respective end faces of a corresponding
one of the core segments 10. The end faces are located on the two respective sides in
the axial direction (the direction of arrow Z). Thus, while the upper end face and the
5 lower end face of each of the core segments 10 are insulated from a corresponding one
of the coils 5, the positions of the slot insulators 7 in the top-bottom direction are
regulated.
[0050]
The stator core includes the shoes 10c at the distal portion 10b1 of each of the
10 teeth 10b. The shoes 10c project from the two respective peripheral-direction ends of
the distal portion 10b1. The slot insulators 7 each include the shoe-covering portions
7c that cover the shoes 10c forming portions of a corresponding one of the slot inner
peripheral walls. The pairs of end-face insulators 4 have the slits (the slits 2b1 and the
slits 3b1) in which the end areas of the shoe-covering portions 7c are secured. The
15 end areas are located on the two respective sides in the axial direction.
[0051]
Thus, the shoe-covering portions 7c of the slot insulators 7 are made to extend
along the shoes 10c of the core segments 10, whereby the shoe-covering portions 7c
are made less likely to slack. Therefore, the probability of wrapping of the shoe20 covering portions 7c during winding is reduced. Consequently, the probability of
disarray in the windings of wire lines is more assuredly reduced.
[0052]
The slot insulators 7 each further include the back-yoke-covering portion 7a that
covers the back yokes 10a forming portions of a corresponding one of the slot inner
25 peripheral walls, and the tooth-covering portions 7b that cover the respective teeth 10b
forming portions of the corresponding slot inner peripheral wall. One of the end-face
insulators 4 in each pair (that is, the upper end-face insulator 2) includes the pressing
parts (the end parts 2d1 of the stepped portion 2d) that each press a corresponding one
of the slot insulators 7 toward the core segment 10 at the boundary between the tooth30 covering portion 7b and the back-yoke-covering portion 7a.
22
[0053]
Thus, the shape of the slot insulators 7 is retained such that the tooth-covering
portions 7b and the back-yoke-covering portions 7a extend along the core segments 10.
Therefore, the probability of wrapping of the tooth-covering portions 7b and the back5 yoke-covering portions 7a during winding is reduced. Consequently, the probability of
disarray in the windings of wire lines is more assuredly reduced.
[0054]

Fig. 16 illustrates a longitudinal section of a compressor including the stator
10 illustrated in Fig. 1. Referring to Fig. 16, a rotary compressor 300 to which the above
stator 34 is applied will now be described. The rotary compressor 300 is intended for,
for example, air-conditioning apparatuses and includes a hermetic container 307; a
compressing element 301, which is provided inside the hermetic container 307; and an
electric motor 100, which is configured to drive the compressing element 301. The
15 electric motor 100 includes the above stator 34, a rotor 33, and other relevant elements.
The rotor 33 is rotatable relative to the stator 34.
[0055]
The compressing element 301 is configured to compress refrigerant. The
compressing element 301 includes a cylinder 302, which has a cylinder chamber 303; a
20 shaft 37, which is to be rotated by the electric motor 100; and a rolling piston 304, which
is fitted on the shaft 37. The compressing element 301 further includes vanes (not
illustrated), which divide the cylinder chamber 303 into a space for suction of the
refrigerant and a space for compression of the refrigerant; and an upper frame 305 and
a lower frame 306, through which the shaft 37 extends and with which the end faces of
25 the cylinder chamber 303 in the axial direction are closed. The upper frame 305 is
provided with an upper discharge muffler 308. The lower frame 306 is provided with a
lower discharge muffler 309. The refrigerant is to be discharged through the upper
discharge muffler 308 and the lower discharge muffler 309 into the space inside the
hermetic container 307.
30 [0056]
23
The hermetic container 307 is a cylindrical container including a lid member and a
bottom member. A glass terminal 311 is fixed to the lid member of the hermetic
container 307. Refrigerating machine oil (not illustrated) that lubricates sliding parts of
the compressing element 301 is stored at the bottom member of the hermetic container
5 307. The shaft 37 is rotatably held by the upper frame 305 and the lower frame 306,
which serve as bearings. The rolling piston 304 eccentrically rotates inside the cylinder
chamber 303 provided in the cylinder 302. The shaft 37 includes an eccentric shaft
portion, on which the rolling piston 304 is fitted.
[0057]
10 The stator 34 of the electric motor 100 is fitted into the hermetic container 307 by
a technique such as shrink fitting, press fitting, or welding and is fixed to the inner
peripheral surface of the hermetic container 307. Electric power is supplied to the coils
5 of the stator 34 through the glass terminal 311. The rotor 33 of the electric motor 100
includes a permanent magnet 35 and a rotor core 36. A shaft hole is provided in the
15 center of the rotor core 36. The shaft 37 is fixed in the shaft hole of the rotor 33. In
the electric motor 100, the rotor is positioned on the inner side of the stator 34. The
shaft 37 extends through the shaft hole of the rotor 33, thereby extending on the center
axis O (Fig. 1) of the stator 34.
[0058]
20 An accumulator 310, which stores refrigerant gas, is attached to the hermetic
container 307 on the outside of the hermetic container 307. A suction pipe 313, which
is connected to the accumulator 310, is fixed to the hermetic container 307. The
refrigerant gas is supplied from the accumulator 310 to the cylinder 302 in the hermetic
container 307 through the suction pipe 313. A discharge pipe 312, through which the
25 refrigerant is discharged to the outside, is attached to the lid member of the hermetic
container 307.
[0059]
Now, an operation of the rotary compressor 300 will be described. The
refrigerant gas supplied from the accumulator 310 flows through the suction pipe 313
30 into the cylinder chamber 303 of the cylinder 302. With the energization of an inverter
24
(not illustrated), the electric motor 100 is activated, whereby the rotor 33 rotates. With
the rotation of the rotor 33, the shaft 37 rotates. Accordingly, the rolling piston 304
fitted on the shaft 37 eccentrically rotates in the cylinder chamber 303, whereby the
refrigerant in the cylinder chamber 303 is compressed. The refrigerant compressed in
5 the cylinder chamber 303 flows through the upper discharge muffler 308 or the lower
discharge muffler 309, further flows through a portion such as a vent (not illustrated)
provided in the rotor core 36, and then flows upward inside the hermetic container 307.
The refrigerant having flowed upward inside the hermetic container 307 is discharged
through the discharge pipe 312.
10 [0060]
Regarding the electric motor 100 including the above stator 34, when winding is
performed, the plurality of core segments 10 are in the spread state in which the core
segments 10 are arranged in a line. Therefore, while winding is being performed, the
width of each of the slots 6 between the teeth 10b is greater than in the state where the
15 plurality of core segments 10 are closed to be arranged annularly. Accordingly, the
width of each of the winding nozzles 20 can be increased. Consequently, a thicker
wire can be wound around the teeth 10b. Such a configuration increases the efficiency
of the electric motor 100 and thus increases the output thereof. Hence, applying the
electric motor 100 to the rotary compressor 300 increases the operation efficiency of the
20 rotary compressor 300 and thus increases the output thereof.
[0061]
The electric motor 100 including the stator 34 is applicable not only to the above
rotary compressor 300 but also to other types of compressors.
[0062]
25
Fig. 17 illustrates a refrigerant circuit of a refrigeration cycle apparatus 400, which
includes the compressor illustrated in Fig. 16. Referring to Fig. 17, the refrigeration
cycle apparatus 400 including the above rotary compressor 300 will now be described.
The following description of a configuration of the refrigeration cycle apparatus 400
30 assumes that the refrigeration cycle apparatus 400 is an air-conditioning apparatus.
25
[0063]
As illustrated in Fig. 17, the refrigeration cycle apparatus 400 includes a
refrigerant circuit including the above rotary compressor 300, and also includes a
controller 406, which is configured to control the operation of the refrigeration cycle
5 apparatus 400. The refrigerant circuit is obtained by connecting the rotary compressor
300, a four-way valve 401, a first heat exchanger 402, a decompressor 403, and a
second heat exchanger 404 to one another by a refrigerant pipe 405. The second heat
exchanger 404 is installed, for example, in a room that is a space to be air-conditioned.
The first heat exchanger 402 is installed, for example, outside the room. The controller
10 406 is, for example, a microcomputer and controls operations of the four-way valve 401
and the rotary compressor 300. The four-way valve 401 changes the direction in which
the refrigerant flows.
[0064]
Now, an operation of the refrigeration cycle apparatus 400 will be described.
15 The rotary compressor 300 compresses the refrigerant sucked thereinto and delivers
the refrigerant in the form of high-temperature, high-pressure gas refrigerant. The solid
lines illustrated in Fig. 17 means that the four-way valve 401 is in a first connection
state, in which the four-way valve 401 allows the refrigerant delivered from the rotary
compressor 300 to flow toward the first heat exchanger 402. When the four-way valve
20 401 is in the first connection state, the first heat exchanger 402 serves as a condenser.
The first heat exchanger 402 causes the refrigerant delivered from the rotary
compressor 300 and air (outdoor air, for example) to exchange heat therebetween, and
then delivers the refrigerant. In the first heat exchanger 402, the refrigerant transfers
heat to the air, thereby being condensed into liquid. The decompressor 403 expands
25 the liquid refrigerant delivered from the first heat exchanger 402 and delivers the
refrigerant in the form of low-temperature, low-pressure liquid refrigerant. When the
four-way valve 401 is in the first connection state, the second heat exchanger 404
serves as an evaporator. The second heat exchanger 404 causes the lowtemperature, low-pressure liquid refrigerant delivered from the decompressor 403 and
30 air (air in the space to be air-conditioned, for example) to exchange heat therebetween,
26
and then delivers the refrigerant. In the second heat exchanger 404, the refrigerant
takes away from the air, thereby being evaporated into gas. In this process occurring
in the second heat exchanger 404, the air having exchanged heat with the refrigerant is
cooled. The cooled air is supplied to the space to be air-conditioned (the room, for
5 example) by a fan, which is not illustrated. Thus, the space to be air-conditioned is
cooled. The gas refrigerant delivered from the second heat exchanger 404 flows
through the four-way valve 401 to the rotary compressor 300 and is compressed by the
rotary compressor 300 again. Thereafter, the above cycle is repeated.
[0065]
10 The broken lines illustrated in Fig. 17 means that the four-way valve 401 is in a
second connection state, in which the refrigerant delivered from the rotary compressor
300 is supplied to the second heat exchanger 404. In this state, the second heat
exchanger 404 serves as a condenser, whereas the first heat exchanger 402 serves as
an evaporator. Accordingly, when the four-way valve 401 is in the second connection
15 state, the space to be air-conditioned is heated.
[0066]
To summarize, the compressor (rotary compressor 300) according to
Embodiment 1 of the present disclosure includes the electric motor 100 including the
stator 34 and the rotor 33 that is rotatable relative to the stator 34. The compressor
20 further includes the compressing element 301 configured to be driven by the electric
motor 100 and to compress refrigerant. Thus, the operation efficiency of the
compressor (rotary compressor 300) is increased. Accordingly, the output of the
compressor is increased.
[0067]
25 The refrigeration cycle apparatus 400 according to Embodiment 1 of the present
disclosure includes the refrigerant circuit in which the compressor (rotary compressor
300), the first heat exchanger 402, the decompressor 403, and the second heat
exchanger 404 are connected to one another by the refrigerant pipe 405. Since the
refrigeration cycle apparatus 400 includes the rotary compressor 300 having an
30 increased output, the operation efficiency of the refrigeration cycle apparatus 400 is
27
increased. Accordingly, the energy efficiency of the refrigeration cycle apparatus 400
is increased.
[0068]
The refrigeration cycle apparatus 400 including the rotary compressor 300 is not
5 limited to the above air-conditioning apparatus. The refrigerant circuit of the
refrigeration cycle apparatus 400 is not limited to the above refrigerant circuit and can
be changed as appropriate. For example, the four-way valve 401 may be omitted from
the refrigeration cycle apparatus 400.
[0069]
10 Embodiment 2
Fig. 18 illustrates a configuration of a part of a stator according to Embodiment 2
that is spread out before winding is performed, as seen in a direction from teeth thereof
toward the outer side. Fig. 19 illustrates a section of the stator illustrated in Fig. 18,
taken along line C-C. Fig. 20 illustrates a section of the stator illustrated in Fig. 18,
15 taken along line D-D. The stator 34 according to Embodiment 2 is different from the
stator 34 according to Embodiment 1 in the configuration of the joint-covering parts 70
included in the back-yoke-covering portions 7a of the slot insulators 7. Referring to
Figs. 18 to 20, the difference in the stator 34 according to Embodiment 2 from the stator
34 according to Embodiment 1 will be described.
20 [0070]
In Embodiment 1 described above, as illustrated in Figs. 10 to 12, the jointcovering part 70 of each of the slot insulators 7 has the projection 71 projecting toward
the axis and provided in the central area 70c in the axial direction. However, the
projection 71 is provided in neither of the end areas of the joint-covering part 70 that are
25 located on the two respective sides in the axial direction. As illustrated in Fig. 18,
similar to the case of Embodiment 1, the stator 34 according to Embodiment 2 has
projections 72, provided in the joint-covering parts 70 of the back-yoke-covering
portions 7a of the slot insulators 7. However, the projections 72 of the stator according
to Embodiment 2 that are provided in the central area 70c in the axial direction are
28
different from those of the stator according to Embodiment 1 in the projecting direction
thereof and the positions thereof.
[0071]
As illustrated in Fig. 19, the joint-covering parts 70 of the back-yoke-covering
5 portions 7a of the slot insulators 7 that cover the joints 10r have the projections 72,
which each extend in the axial direction (the direction of arrow Z) and project radially
outward. As illustrated in Fig. 18, each of the joint-covering parts 70 of the slot
insulators 7 has two projections 72, each of which has a predetermined length in the
axial direction (the direction of arrow Z). The projections 72 projecting radially outward
10 are provided only in the upper end area 70a and the lower end area 70b of the jointcovering part 70 of the back-yoke-covering portion 7a, not in the central area 70c of the
joint-covering part 70 in the axial direction (the direction of arrow Z). In the spread
state illustrated in Fig. 20, the central area 70c of the joint-covering part 70 in the axial
direction (the direction of arrow Z) is substantially flat along the inner surfaces 10ai of
15 the back yokes 10a.
[0072]
To summarize, the electric-motor stator 34 according to Embodiment 2 includes
the stator core including the plurality of core segments 10 annularly joined to one
another, the coils 5, and the insulator 8 insulating the core segments 10 and the coils 5
20 from each other. The core segments 10 each include the arc-shaped back yoke 10a,
and the tooth 10b extending from the peripheral-direction center of the inner surface
10ai of the back yoke 10a toward the center axis O. The coils 5 are wound around the
respective teeth 10b of the core segments 10. The stator core has the slots 6 each of
which is provided between adjacent two of the teeth 10b and in which the coils 5 are
25 positioned. The insulator 8 includes the slot insulators 7 each being continuous in
such a manner as to cover a corresponding one of the slot inner peripheral walls of the
stator core. The slot insulators 7 each include the joint-covering part 70 that covers the
joint 10r where two of the back yokes 10a are joined to each other. The joint 10r forms
a portion of the corresponding slot inner peripheral wall. The joint-covering part 70 has
29
the projections 72 projecting radially outward and provided only in the end areas on the
two respective sides in the axial direction (the direction of arrow Z).
[0073]
Thus, the shape of the joint-covering part 70 of each of the slot insulators 7 is
5 stabilized by the projections 72 projecting radially outward and provided in the end
areas of the joint-covering part 70 that are located on the two respective sides in the
axial direction (the direction of arrow Z). Furthermore, the joint-covering part 70 has no
structure projecting into the slot 6 in either the end areas on the two respective sides in
the axial direction or the central area 70C. Such a configuration according to
10 Embodiment 2, as with the case of Embodiment 1, reduces the probability of wrapping
of the joint-covering part 70 of the slot insulator 7 that may occur when the winding
nozzle 20 changes the direction of movement thereof at the end of each of the teeth
10b during winding. Thus, the proper arrangement of wire lines is ensured.
Accordingly, the electric-motor stator 34 has a low probability that the space factor of
15 the coils 5 may be reduced because of disarray in the windings of wire lines.
[0074]
As with the case of Embodiment 1, the stator 34 according to Embodiment 2 is
applicable to the rotary compressor 300. Such an application also increases the
operation efficiency of the rotary compressor 300 and thus increases the output thereof.
20 As with the case of Embodiment 1, the compressor (rotary compressor 300) to which
the stator 34 according to Embodiment 2 is applied is applicable to the refrigeration
cycle apparatus 400. Such an application increases the energy efficiency of the
refrigeration cycle apparatus 400.
[0075]
25 Note that any change such as modification or omission can be made as
appropriate in each of Embodiments 1 and 2. For example, while Embodiments 1 and
2 each relate to the stator 34 that is formed of nine stator segments, the number of
stator segments forming the stator 34 is not limited thereto.
Reference Signs List
30 [0076]
30
1: iron core piece, 2: upper end-face insulator, 2a: outer flange, 2b: inner flange,
2b1: slit, 2bi: inner surface, 2c: tooth-end-face-covering portion, 2c1: end part, 2d:
stepped portion, 2d1: end part, 2e: inclined portion, 2e1: end part, 3: lower end-face
insulator, 3a: outer flange, 3b: inner flange, 3b1: slit, 3c: tooth-end-face-covering
5 portion, 3e: inclined portion, 3f: wiring groove, 4: end-face insulator, 5: coil, 5a:
conductive wire, 6: slot, 7: slot insulator, 7a: back-yoke-covering portion, 7b: toothcovering portion, 7c: shoe-covering portion, 8: insulator, 10: core segment, 10a: back
yoke, 10b: tooth, 10c: shoe, 10g: gap, 10i: inner surface, 10r: joint, 20: winding nozzle,
21: jig, 33: rotor, 34: stator, 35: permanent magnet, 36: rotor core, 37: shaft, 50: stator
10 segment, 70: joint-covering part, 71: projection, 72: projection, 100: electric motor, 300:
rotary compressor, 301: compressing element, 302: cylinder, 303: cylinder chamber,
304: rolling piston, 305: upper frame, 306: lower frame, 307: hermetic container, 308:
upper discharge muffler, 309: lower discharge muffler, 310: accumulator, 311: glass
terminal, 312: discharge pipe, 313: suction pipe, 400: refrigeration cycle apparatus, 401:
15 four-way valve, 402: first heat exchanger, 403: decompressor, 404: second heat
exchanger, 405: refrigerant pipe, 406: controller, O: center axis
31
We Claim :
[Claim 1]
An electric-motor stator comprising:
a stator core including a plurality of core segments that are annularly joined to
5 one another, the core segments each including an arc-shaped back yoke and a tooth,
the tooth extending from a peripheral-direction center of an inner surface of the back
yoke toward a center axis;
coils wound around the respective teeth of the core segments; and
an insulator insulating the core segments and the coils from each other,
10 wherein the stator core has slots each of which is provided between adjacent two
of the teeth and in which the coils are positioned,
wherein the insulator includes
slot insulators positioned in the respective slots and each being continuous in
such a manner as to cover a corresponding one of slot inner peripheral walls of the
15 stator core,
wherein the slot insulators each include a joint-covering part that covers a joint
where two of the back yokes are joined to each other, the joint forming a portion of the
corresponding slot inner peripheral wall, and
wherein the joint-covering part has a projection projecting toward the center axis
20 and provided only in a central area of the joint-covering part in an axial direction, or
projections projecting radially outward and provided only in end areas of the jointcovering part that are on two respective sides in the axial direction.
[Claim 2]
The electric-motor stator of claim 1,
25 wherein the insulator includes
pairs of end-face insulators, the end-face insulators in each pair being attached to
respective end faces of a corresponding one of the core segments, the end faces being
located on the two respective sides in the axial direction.
[Claim 3]
30 The electric-motor stator of claim 2,
32
wherein the stator core includes shoes at a distal portion of each of the teeth, the
shoes projecting from two respective peripheral-direction ends of the distal portion,
wherein the slot insulators each include shoe-covering portions that cover the
shoes forming portions of a corresponding one of the slot inner peripheral walls, and
5 wherein the pairs of end-face insulators have slits in which end areas of the shoecovering portions are secured, the end areas being located on the two respective sides
in the axial direction.
[Claim 4]
The electric-motor stator of claim 2 or 3,
10 wherein the slot insulators each include a back-yoke-covering portion that covers
the back yokes forming portions of a corresponding one of the slot inner peripheral
walls; and tooth-covering portions that cover the respective teeth forming portions of the
corresponding slot inner peripheral wall, and
wherein at least one of the end-face insulators in each pair includes pressing
15 parts that each press a corresponding one of the slot insulators toward the core
segment at a boundary between the tooth-covering portion and the back-yoke-covering
portion.
[Claim 5]
A compressor comprising:
20 the electric motor including the electric-motor stator of any one of claims 1 to 4,
and a rotor that is rotatable relative to the electric-motor stator; and
a compressing element configured to be driven by the electric motor and to
compress refrigerant.

33
[Claim 6]
A refrigeration cycle apparatus comprising:
a refrigerant circuit in which the compressor of claim 5, a first heat exchanger, a
decompressor, and a second heat exchanger are connected to one another by a
5 refrigerant pipe.